Dwain Chambers will not find out until tomorrow if his lifetime Olympics ban will be lifted so he can compete in the Beijing Games.

The sprinter was in the High Court today seeking an injunction against the suspension imposed on him because of his past use of performance-enhancing drugs.

Jonathan Crystal, representing the athlete, is trying to convince Mr Justice Mackay that the British Olympic Association by-law is unfair and an unreasonable restraint on trade.

But after hearing Crystal's arguments in favour of Chambers, 30, being allowed to compete in the 100 metres in China next month, Justice Mackay confirmed there would be no decision until tomorrow. As the International Olympic Committee rule that all teams must be named before Sunday it means neither side will have time to appeal, so Justice Mackay's verdict will be final.

Today, Crystal began his case with his client sat behind him in Court 76 wearing a black suit and red tie and sipping bottled water.

Chambers tested positive for the steroid THG and has already served a two-year ban ending in 2006 but remains excluded from Olympic competition. He said Britain's rules were much tougher than those of the IOC.

Crystal said: "Drugs at the Olympics is nothing new. The view of the IOC as to who participates in the Games should not be lightly rejected. Mr Chambers is eligible and welcome in Beijing. "He has completed his sanction and has acknowledged his guilt."

Crystal said the ban was an unreasonable restraint of trade which was contrary to competition law. He added that the BOA's lifetime ban was out of step with the new anti-doping rules of the IOC and rejected the BOA's claim that Chambers was denying a place to another British athlete.

In his opening remarks, David Pannick, QC, for the BOA, said the charter of the IOC gave his client the discretion to exclude drugs cheats.

He said: "It's for the national Olympic Committees to make their own selection not only on who can run fastest but who can serve as an example to youth."