Some people might wonder what the fuss is over the 90-day law since trial periods are not unknown in some employment contracts. The problem is not the trial period but the removal of all appeal rights along with it.

Fair dismissal is acceptable but this change legislates for unfair dismissal. Trial periods are about the fair appraisal of someone's ability to do a job. You set targets and monitor progress, and sometimes in the end you arrive at an honest and open assessment, visible to both parties, that someone is not up to it.

Dismissing them because they are not good enough for the job after having a fair chance is not what unions have a problem with.

What we do have a problem with is that the 90-day law allows employers to sack new workers for anything, or even nothing at all. If a new employee pointed out a health and safety risk, the employer could sack them a few days later without giving any justification.

Or the employer's nephew needs a job, so the newest worker gets sacked to make space. Those are self- evidently unfair dismissals and, no matter how much evidence there was, the employee would be powerless to defend their character and employment record.

Here are some real examples that came to us after the 90-day law was introduced. In one case a bar owner formed a new company, forced an employee to sign a new contract containing a 90-day clause and sacked them shortly afterwards in order to appoint an acquaintance to the vacated post. A similar case was of a shop worker sacked for no reason by new owners when the retail business changed hands.

We also learned of a woman taken on by a call centre. Her hearing impairment (of which the employer was aware at the time of hiring) required special equipment but, instead of providing it, they changed their minds and simply fired her under the 90-day law.

While discriminating because of her disability was unlawful, proving that when no reason need be given and no processes followed makes a personal grievance impossible.

In another example, a new worker in a communications company turned up for work to find the office being renovated. Unable to provide alternative facilities, the company simply fired the worker.

These cases have nothing to do with the inability of the worker to do their job and everything to do with employers exploiting the ability to dispense with workers without bearing responsibility for treating them in what is self-evidently an unfair and indefensible manner.

The 90-day law, therefore, is a charter for unfair dismissal and a Trojan horse for an attack on basic democratic workplace rights. Excluding the right to appeal against obviously unfair sacking goes far beyond the law's spurious justification of increasing employment (which it doesn't do either).

By making new workers completely vulnerable to summary dismissal it applies unacceptable pressure on a worker's freedom to choose to join a union, to report malpractice, or to draw attention to safety concerns.

Helen Kelly is president of the Council of Trade Unions.