WILL THE love-in, announced to the world in the Rose Garden of No 10 Downing Street last Wednesday between new British prime minister David Cameron and Liberal Democrat leader Nick Clegg, last?

Or will thorns appear in the relationship as they have to implement savage cutbacks? Coalition government is not the British way. Last week's deal marked the UK's first coalition government in 70 years, the first time the Conservatives and the Liberal Democrats have agreed to a power-sharing deal at national level in the UK.

We have had coalition governments in Ireland for decades. So what advice could we offer Cameron and Clegg? What makes a good coalition? And what are the pitfalls they need to avoid?

Many parallels may be drawn between the British and Irish situations. The actions of Gordon Brown alone last week echoed Irish politics in 1948.

Before the Cameron-Clegg deal, Brown said he was prepared to walk off the pitch to make it easier for Clegg do a deal with Labour. Brown was prepared to do a 'Richard Mulcahy'.

Mulcahy was one of the most controversial figures in the early decades of the Irish Free State. As commander-in-chief of the Free State army and minister for defence he was hated in some quarters for being the minister responsible for the execution of key anti-Treaty figures, who were heroes in the War of Independence.

Much later he became the leader of Fine Gael in 1944 and organised the first inter-party government in 1948. But Clann na Poblachta could not stomach being led in government by the commander of the Free State forces during the Civil War. So Mulcahy stood aside to allow John A Costello become Taoiseach.

Brown was prepared to step down last week and allow a party colleague, such as one of the Milibands, play the Costello role.

But it did not come to that. The Clegg and Cameron double act was born. And both men have solemnly declared that their coalition experiment will last five years.

So what are the ingredients for a successful coalition?

Former Labour party leader Pat Rabbitte was a junior minister in the Rainbow Coalition, made up of Fine Gael, Labour and Democratic Left from 1994 to 1997.

He told the Sunday Tribune: "Compatibility of policy would be a great help in establishing a successful coalition government. No two parties will agree on everything but they must be able to agree on a fair measure of issues, especially on the critical issues. Where that is not present then a programme for government must be painstakingly worked out.

"I don't know if that has been done in the British case. It would appear that the Conservatives have taken a couple of issues that are dear to the hearts of the Liberal Democrats and compromised on them but they have yet to agree on the substantive issues in a programme for government. That might lead to problems as these substantive issues will have to be dealt with as they come up. They should leave as little as possible to chance as there will be other unforeseen issues that will come up."

He believes that tensions between party leaders in a coalition lead to their downfall, as has been the case in Ireland.

"I think that the ones that have gone wrong over here during the Coalition era were the ones where pronounced personal chemistry at the top was the problem. This happened between Dick Spring and Albert Reynolds and between Des O'Malley and Reynolds. It can come down to personalities.

"On the other hand, Bertie Ahern fostered almost a mesmeric effect in coalition. Even though Michael McDowell had clearly the most fundamental reservations about Mr Ahern's creative personal financing, Ahern kept the PDs on board and developed an extraordinary relationship with Mary Harney."

One of the now defunct Progressive Democrats' greatest achievements was forcing Fianna Fáil to concede its core principle of never going into coalition with another party.

From 1986 to 1995, Stephen O'Byrnes worked as director of policy and press relations for the PDs. He was assistant government press secretary from 1989 to 1992 for the Fianna Fáil-PD coalition government.

Events in Downing Street last week reminded him of the days when he was in the thick of the coalition action. "The key thing is trust. That is critical. It is not just convenience. There has to be trust. There is an onus on the larger party to be generous towards the smaller entity. Politics is the art of the possible.

"I was directly involved in the Fianna Fáil-PD coalitions, firstly between Haughey and then Reynolds with Des O'Malley and there was never much trust there. There was huge animosity about Fianna Fáil having to concede what Padraig Flynn called Fianna Fáil's core value of not going into coalition.

"While there might not have been a lot of trust, the professional attitude held by Haughey and O'Malley made it work.

"When Reynolds came in February 1992, after succeeding Haughey, the coalition was gone within eight months. There was a professional relationship between Haughey and O'Malley but Reynolds was hell-bent on bringing an end to the relationship."

Both Rabbitte and O'Byrnes agree the success of coalitions is largely dependent on the relationship between the party leaders.

Much has already been made of the obvious bonhomie between Clegg and Cameron that was apparent during their Rose Garden press conference. But O'Byrnes offered some solid advice on coalitions. As well as the leaders and their TDS or MPs having a compatible working relationship, they also need robust people behind the scenes.

"When I look back on Irish coalitions, they need a lot of support structures if they are to work. And in that government [the Reynolds-O'Malley coalition], they were not there. Immediately afterwards, in January 1993, the Labour government brought in a programme manager for each department and there is no doubt that would have helped."

When the Labour-Fianna Fáil government formed in November 1992, Labour leader Dick Spring made sure the correct support structures were in place to back up his team in coalition by the time the government first met in January 1993.

"You still have the programme managers today and they meet before the weekly cabinet meetings," said O'Byrnes. "They are filtering machines for resolving inter-party issues. Prior to 1993 that model did not exist and there was very little support resources.

"I am sure that the UK model will have lots of support mechanisms. From our own experience since the collapse of that Fianna Fáil-Progressive Democrats coalition, they have worked in Ireland."

So what hurdles might prove insurmountable for Cameron and Clegg? What makes coalitions fail?

"When they don't work, it is usually due to unreasonable demands from the larger party", says O'Byrnes. "Alternatively, the smaller party is always looking over its shoulder politically to know if it should take it through to the end of the five years or engineer a cut-and-run scenario to give them a boost before they go before the people. That is always a dilemma for a smaller party and it will face the Liberal Democrats.

"Between 1997 and 2002 when you had the coalition between Bertie Ahern and Mary Harney, she could have pulled the plug at a number of different times. So coalition works to the advantage of the larger party.

"If the smaller party signs up for five years, that can make it more difficult to break up the coalition as it can be seen as opportunism.

"The Greens have already signed up to swingeing cuts and harsh budgets. If they were to try to cut and run now, they would have to convince us what is so unique about the issue that they have decided to leave on [given that they have stayed in government and supported cuts to date]."

A marked feature of some recent Irish coalition governments has been the use of a figure in the smaller party to play the role currently played by Green party Senator Dan Boyle in the current Fianna Fáil-Green coalition.

Replicating a role previously played by Michael McDowell for the PDs, Boyle regularly publicly questions the actions of his own party in government. He marched the Greens to the edge of the cliff a number of times. While he may have impressed some Green party members with his bravado, he could also be accused of crying 'wolf' for his actions.

It is unclear if the Liberal Dems will cast somebody in this role. Surely, there is only one Dan Boyle?

Irish Coalitions

1948-51 Fine Gael, Labour, Clann na Poblachta, Clann na Talmhan, National Labour

1954-57 Fine Gael, Labour, Clann na Talmhan

1973-77 Fine Gael, Labour

1981 Fine Gael, Labour

1982-87 Fine Gael, Labour

1989-92 Fianna Fáil, Progressive Democrats

1992-94 Fianna Fáil, Labour

1994-97 Fine Gael, Labour, Democratic Left

2000-07 Fianna Fáil, Progressive Democrats

2007-09 Fianna Fáil, Green, Progressive Democrats

2009 Fianna Fáil, Green