Sedgley marathon man Martin Williams after Olympics place

Martin Williams runs the London Marathon tomorrow, bidding to bag an Olympic place.

The first Brit past the post will qualify for London 2012 and Williams, from Sedgley, is determined to take his big chance.

Two hours and 12 minutes – the Olympic 'A' standard – is the time to hit while Tipton Harrier Williams' previous best is 2hrs 17mins.

Scott Overall is the only man to have run the Olympic time and, having been pre-selected for 2012, will be the official pacemaker tomorrow. But Williams, who works as a policeman in Walsall, insisted if he is going to claim one of the two spots left – although Leeds' David Webb has already run the 'B' standard and is favourite to take one place – then he must run his own race.

"I've decided I'm just going to race," said Williams, who finished 13th in the European Cross Country Championships last month.

"When I won in Edinburgh (the marathon in 2009) I didn't look at split times, I just thought 'I'm going to race.'

"My best marathons are when I tend to start off a little bit slower because you can go too quickly until half way. I'm not going to do that. It's a game of chess but I'm still confident I can finish as top Brit – that's what I'm focusing on.

"It's going to be a hard time to get anyway but, at that pacemaker speed, won't work for me.

"Basically there's going to be casualties, because a lot of people go off at two hours 10 minutes pace and they can't sustain it. It's how you respond to it on the day.

"I've always been excited by the big occasions and most of the time I've got it right.

"On the ranking list I'm half way, towards the bottom, but there are guys there who have got a bit more to prove as they've been training full time, that's what motivates me."

The real contenders have been reduced from 12 to 10 after Williams' Harriers team-mate Phil Nicholls, from Perton, pulled out with a calf problem and Phil Wicks is missing with a hamstring injury.