He resembled anything but the lethal assassin of Railtrack demonisation

Stephen Byers checked that his mobile was switched off, gave his counsel a nervous smile and, pausing only to take a gulp of water, walked up and took the stand.

The House of Commons is the crucible in which most political reputations get made - or melted down. But in Mr Byers' case, the venue is Court 62 in the Royal Courts of Justice on the Strand.

How well he stands up under cross-examination over the next two days could determine whether the former secretary of state for transport and New Labour favourite has a future in politics, or just a past.

The tiny court - for some reason Mr Justice Lindsay decided it was not necessary to move to a larger one - was packed for the occasion, with reporters and Railtrack shareholders jostling for the 25 seats in the public gallery.

The former Cabinet minister was the star turn that everyone had been waiting for. Byers, Byers, pants on fire; the man who pulled the rug from under Railtrack. The clerk to the court asked him to take the oath and out came the familiar response ... the truth, the whole truth and nothing but the truth.

Over the past 12 days, some ripe accusations have been levelled at Mr Byers: that he acted with "targeted malice" in shunting Railtrack into administration; that his was the "kiss of death"; that he was the man who delivered the "hammer blow" to all those "grannies" who made up the Railtrack shareholder register.

Dressed in a charcoal-grey suit, white shirt and maroon tie, the bespectacled Mr Byers resembled anything but the lethal assassin. In fact he looked exactly like the polytechnic lecturer in law that he once was before Parliament beckoned.

Keith Rowley QC, for the shareholders, put it to Mr Byers that he acted with the specific intent of robbing them of their company. Mr Byers replied that it was a very serious allegation but it was simply wrong.

Why then, had he described Railtrack as a "basket case" and how had one of Gordon Brown's special advisers, Shriti Vadera, come to e-mail her Treasury colleagues immediately after a meeting with Mr Byers to inform them that he wanted a new owner for Britain's railways. "Shriti is a sweetie" Mr Byers replied, before adding that he had no recollection of saying such a thing and no idea why such an e-mail was sent.

Court 62 is likely to hear plenty more in this vein over the next couple of days. The case continues. But will Mr Byers' Cabinet career do likewise?