Dwain Chambers's hopes of overturning his lifetime Olympics ban in time for the Beijing Games were kept alive in the High Court today.

The disgraced sprinter was at the London hearing as his lawyers launched an appeal against the British Olympic Association's bylaw stopping athletes found guilty of doping offences competing in the Games.

And while the High Court ruled a full hearing would not be held until next year, it will decide whether to grant Chambers an injunction during a one-day hearing next Wednesday.

Today's decision is a relief for Chambers because he feared the BOA, who are vigorously defending their rule, would try to block his bid for Beijing by having the case heard after next month's Olympics. Justice Mackay agreed that given the late timing of Chambers's appeal, a full trial could not be heard until next March.

It means Chambers can still force his way into the team by qualifying at this weekend's British Olympic trials in Birmingham but could then be kicked out just days later if he loses his injunction fight.

Chambers's lawyers will argue that the ban, on top of a mandatory two-year suspension already served for using designer steroid THG in 2003, is an unreasonable restraint of trade which is also "inherently unfair and unreasonable".

After his High Court appearance, Chambers said: "Friday and Saturday is when the job matters. I'm capable of doing the job my end which is to cross the line first. It was pretty tough in (court) this morning."

Colin Moynihan, chairman of the BOA, said: "We will continue to vigorously defend the bylaw."

On Friday Chambers, 30, is due to line up for the heats of the 100metres, for which he is the clear favourite, at Birmingham's Alexander Stadium. Following the three-day trials, UK Athletics and the BOA will announce the majority of the team on

Monday with the final deadline for selection on 20 July.

Meanwhile, Britain's former triple jump world champion Ashia Hansen, 36, has retired after losing her battle to be fit for Beijing. She has struggled for form after a knee injury in 2004.