Chambers is currently prohibited from competing at Beijing 2008
Dwain Chambers has boosted his campaign to reach the Beijing Olympics by twice running inside the Olympic qualifying standard at a meeting in Germany.
The sprinter clocked 10.06 seconds in his 100m final in Biberach, bettering his 10.14 in the afternoon heats - both easily within the Olympic 'A' standard.
"I've matured a lot and I'm proving I can do it clean," said Chambers.
The British Olympic Association (BOA) has banned Chambers from Beijing but he is expected to challenge the ruling.
"I will always remain a clean athlete from here onwards," added the 30-year-old following his final.
"I've come of age now and I believe in what I say and I'm able to do the walking as well. That comes with age, experience and confidence.
It's only a matter of time before I will be able to show what I can do when I get into the Olympic final
"Now I've got the qualifier, I've just got to continue with my role which is competing and let the lawyers do their part."
Nick Collins, Chambers' solicitor, confirmed: "The legal papers are presently with his barrister and we are anticipating serving them next week."
Chambers had wanted to reach the Olympic qualifying time before proceeding with legal action against the BOA's ban.
"I was more concerned in the heat with just getting the qualifier," he admitted.
"That was playing on my mind a bit. Once I had achieved what I did, it just made the opportunity of coming out in the final more comfortable.
"It's only a matter of time before I will be able to show what I can do when I get into the Olympic final."
He has had several attempts at the mark over the last few months, but his previous best for the season was a time of 10.24, set at the Southern Counties Championships earlier in June.
His best time in Germany - eventually rounded down from 10.07 to 10.06 by judges - is 0.15 seconds inside the 'A' standard, and fractionally ahead of the time he achieved when returning from suspension in 2006.
It places him joint top of the British rankings with Tyrone Edgar, but he remains prohibited from competing in Beijing this summer.
I presume he will challenge the British Olympic Association by law, which he said he would do if got the qualifying time
London 2012 chairman
A BOA by-law prevents athletes who fail doping tests, as Chambers did for banned steroid THG, from representing Team GB at any Olympic Games.
The British Olympic trials take place on 11 July, with the BOA committed to naming its team for Beijing before 20 July, so any appeal has less than a month to succeed.
Lord Coe, London 2012 chairman and a critic of Chambers' Olympic bid, said the challenge could lead to "six or seven tricky weeks" before Beijing.
"It doesn't surprise me because Dwain is perfectly capable of running an Olympic qualifying time and he has been inching the way there in the last few weeks," Coe told the BBC following Chambers' run.
"I presume he will challenge the British Olympic Association by law, which he said he would do if got the qualifying time.
"It's important to maintain integrity of sport and most importantly protect the 99.9% of athletes who choose to compete fairly."