Former High Court judge Feargus Flood has publicly backed the government's controversial new crime bill and said he had presided over gangland trials where he felt juries had returned the wrong verdict.

In the most outspoken contribution on the bill by a sitting or former judge, Flood said justice minister Dermot Ahern's plans to send gangland trials to the non-jury Special Criminal Court were necessary to "maintain order".

"Until we take a firm stand, these people will walk over us," he said. "Steps have to be taken to bring this under control. Otherwise, it's unbelievable what could happen to society.

"If you have a problem with juries and intimidation – which we obviously have – three to five High Court judges [presiding over gangland trials in the Special Criminal Court] would be reasonable."

Flood said he had not witnessed jury or witness intimidation first-hand as a judge but over the course of his career, juries had brought back what he felt was the wrong verdict in gangland trials.

"I have seen people get away with it. We have to put gangland criminal trials in the hands of the judiciary rather than the hands of juries. A balance of three to five judges would be certain to get a fair result."

Last Wednesday, 133 solicitors and barristers wrote to the Irish Times saying the legislation may be unconstitutional and Ireland would "be shamed" before the United Nations and the European Court of Human Rights because of the new measures.

Flood said he did not think the group of lawyers "understand the seriousness of the situation".

Asked whether the pace at which the bill has passed through the Dáil – it was passed on Friday and will be considered by the Seanad on Tuesday before being sent on to President Mary McAleese – was too swift, he said: "Has he [Ahern] got any option? Hasn't he got to take control? I accept that it's not a good idea for it to happen at this pace. But the situation has to be controlled."

It is difficult to gauge whether Flood has support among the judiciary and former judges for his views.

A former Supreme Court judge, who spoke on condition of anonymity, described the speed with which the legislation had gone through the Dáil as "unwise".

The bill was debated for less than two weeks.

"It is a very important piece of legislation," Flood said.

"I understand the government wants to do something but I don't think it's wise to guillotine it through the Dáil."

Flood said legislation of this significance should be debated for "several months" because it is "infinitely harder" to amend it once it is signed into law.

Flood said he would support the jailing of gangland criminals without the possibility of parole.

"I served from 1992 to 2007 as a judge, that's 15 years. I've seen what goes on.

"If you have to put them [gangland criminals] in jail for the rest of their lives, that's what you have to do to maintain order. But there should be a provision that if someone served 25 years, he can apply for parole but he has to prove he's rehabilitated. You have no option. You cannot have chaos. You cannot have people shooting the blazes out of innocent people. Innocent victims, it's not on. You must run society on the basis of law and order. The minister has to be reasonable and responsible but he still has to get his job done."

Defence solicitor Frank Buttimer, who is opposed to parts of the legislation, said there was a "very strong possibility" that President Mary McAleese will not sign the bill into law but refer it to the Supreme Court to test its constitutionality. A senior justice source agreed there was "a real chance" this may happen.

"If you have to put them [gangland criminals] in jail for the rest of their lives, that's what you have to do to maintain order. But there should be a provision that if someone served 25 years, he can apply for parole but he has to prove he's rehabilitated. You have no option. You cannot have chaos. You cannot have people shooting the blazes out of innocent people. Innocent victims, it's not on. You must run society on the basis of law and order. The minister has to be reasonable and responsible but he still has to get his job done."