The issues raised by the 'anti gang' Criminal Justice (Amendment) Bill, rushed through the Oireachtas in the last days before summer, are so fundamental to the way we run our legal system that it is vital that they are scrutinised by the Supreme Court to see if they are constitutional before they become law.

The legislation will inevitably be passed by the Seanad when it debates the bill this week – if the Fianna Fáil and Green Party whips get their act together more professionally than they did for the Defamation Act, and ensure they have a majority at the time of the vote.

After that, it is up to President Mary McAleese to decide whether to exercise one of her most important executive functions and convene a meeting of the Council of State to discuss the possibility of referring the proposed law to the Supreme Court to test its constitutionality.

President McAleese did this two years ago after the Oireachtas passed the controversial Criminal Justice Act 2007 (another piece of 'gang-busting' legislation that followed closely on the 'criminal crackdown' that was the Criminal Justice Act 2006, which the new law amends) following an uncannily similar debate in which both sides rehearsed many of the same points that we hear today.

In 2007, after a two-hour meeting with members of the Council of State at Áras an Uachtaráin, President McAleese decided against a Supreme Court referral and the Criminal Justice Act 2007 became law.

Over the past two years, gang crime has clearly worsened, with 16 gang-related murders this year alone. Because of this, and because understandably and rightly, there is such public anger and revulsion over the intolerable actions of the gangs which seem to operate beyond the law, the justice minister Dermot Ahern has put forward even tougher legal constraints.

Everybody acknowledges the threat of the gangs, particularly in areas such as Limerick, Finglas and parts of west Dublin. Their arrogant sense of invincibility and the brazen way they make life hell for ordinary people – neighbours, shopkeepers, schools and local authority workers or anybody who gets in the way – is an indictment of our legal system.

What divides people is the appropriate response, and whether such important and far-reaching legislation should be rushed through an exhausted Dáil and Seanad before their members head off on their outrageously long holidays.

The justice minister's tactic has been to move gang-related crimes into the same legal world as terrorism, with certain crimes classified as 'scheduled' offences, to be tried in the Special Criminal Court before three judges. The opinion of a garda or former garda that an accused is a member of a criminal gang, or a director of a gang, will be allowed as evidence on which a conviction can be based.

The amendments also make it easier to refuse bail and give greater powers of detention without charge.

These new offences are very similar to the laws passed in emergency session after the Omagh bombing, which created the specific crime of directing terrorism, and because they follow this law so closely, the justice minister is sure that, constitutionally, he is on firm ground. Dermot Ahern says the attorney general has advised there are no constitutional problems. Other equally eminent legal minds are less sure.

What is certain is that these changes transform our jury-based system of criminal law so radically that it is highly likely that one of the members of a criminal gang charged under the new legislation will make a constitutional challenge, possibly even taking the case to Europe.

The last thing anyone wants to see – including those who have reservations about this legislation – is a nasty, brutal, murderous gang member walking free from court because the law under which he was charged was knocked down on constitutional grounds.

If that challenge takes place during the highly-charged emotions of a trial, it will inevitably create a blaze of headlines, adding to a criminal's notoriety within his own gang and community.

It will also delay justice for the victim because it could take months, possibly years, to resolve if it goes all the way to Europe.

If, after such a challenge, this law is found to be unconstitutional, the swaggering invincibility felt by these gangsters will surely grow.

It is surely preferable that all constitutional doubts are settled, one way or the other, now, as part of a dry legal review requested by the president.

If, as Dermot Ahern insists, these laws are constitutional, they will gain wider support.

The other point to stress is that those with doubts about this legislation are not opposed to putting gangsters behind bars for very long sentences. The new surveillance law is an important weapon that allows gardaí full use of technological advances now available.

There is widespread support for making gang-related activity a crime, but the concerns about prosecuting gang members without a jury on garda opinion evidence are based on past experience.

The shocking consequences of tainted garda evidence were all too clearly revealed in the Morris tribunal. Is it any wonder that some would prefer that a garda's uncorroborated word not be taken as definitive evidence of a crime?

The role of the gardaí before the Special Criminal Court has not been a happy one either. The Heavy Gang and the Sallins Mail Train trial have cast a long shadow over the force and the Special Criminal Court itself.

The garda handling of the witness-protection programme in the Veronica Guerin trial was roundly criticised by the Court of Criminal Appeal judges who quashed Paul Ward's conviction for murder.

Of course, most gardaí are model protectors of the communities they serve but every powerful institution of state needs checks and balances to ensure its powers cannot be abused.

That is why we have to be so careful about these new laws, and why the president should summon the members of the Council of State to a meeting at their earliest convenience.