In a thinly veiled criticism of Labour and the Progressive Democrats, who have both promised major tax cuts, Sargent told the Green Party conference in Galway: "Now is the time for action, not auctions."

"Everyone remembers the last general election in 2002, when promises were made and then forgotten, " he said. "After the election, these plans were scrapped. That is irresponsible. That is wrong. The next government, including a strong Green party, will be a responsible government."

Outlining the party's plans for transport, Sargent said the Green Party would build more Luas lines in Dublin, Cork and Galway and that rail lines would be re-opened in Limerick, Meath and "all over Ireland".

Promising more teachers, smaller class sizes, safe routes to schools and medical cards for all children under six, Sargent said the Greens would "protect, promote and fulfil the human rights of every child in Ireland".

"Imagine an Ireland in which every child can be safe in their community, " he said.

"The Green Party will put more gardai in our communities. And we will ensure that, after five years, there are safe routes to every single school so that, once again, parents can feel secure in letting their child walk or cycle to school." Sargent also outlined proposals to support offshore wind, wave and tidal power and fast-track Ireland's participation in a European-wide 'super-grid' of electricity transmission.

Highlighting the government's failure to support green-energy enterprise, he said: "At present, Ireland has no department of energyf Ireland needs a department of innovation and sustainability to plan for our energy requirements."

The need to respond to the challenge of climate change has never been so strong and, in the past year, people's attitudes have changed towards the Green Party, Sargent said.

"Now in 2007, the Irish people are realising that green thinking is desirable, necessary and urgent, " he said. "I believe that no one wants politics to be compromised by corporate interests. I believe that the Irish people will support an end to corporate donations in politics. We deserve a democracy in which we can feel pride."