As the Politics Show goes to air thousands of runners have completed 26 gruelling miles around the capital for the 2009 London Marathon.
Each year 10 places on the marathon are reserved for Members of Parliament, yet to date only 42 have taken up the challenge - 20 Labour, 19 Conservative and three LibDems.
MPs times London Marathon 2009
By far the fastest was former Conservative MP Matthew Parris who recorded a time of 2hrs 32min 57sec in 1985.
If Matthew had run that time in the 2009 marathon he would have finished in 79th place.
We asked Matthew for his memories of his record breaking race.
We asked Matthew for his memories of that record breaking race and why he thinks more MPs should don their trainers and run the marathon.
You can see the personal best times for all 42 MPs and former MPs at the bottom of this feature.
This year only three out of 646 MPs are taking part - Labour MPs Howard Stoate and Chris Bryant and Conservative MP Edward Timpson.
MP Chris Bryant talks about running the London Marathon 2009
A fourth Member, Conservative Chief Whip Alistair Burt has been forced to pull out due to injury.
Dr Stoate is a veteran marathon runner and is the ninth fastest MP overall.
He thinks more MPs should take up marathon running.
MP Edward Timpson talks about running the London Marathon 2009
Conservative Edward Timpson is running for the first time as an MP, but he is an experienced marathon runner.
Chris Bryant, Labour MP for Rhondda says he is hoping for better weather than last year.
Marathon men - Bryant, Stoate and Timpson
But what about all those MPs and former MPs who have run the London Marathon but did not take part this year?
We asked some of them for their memories.
Labour MP Doug Henderson is the second fastest MP and only the second to run under three hours.
Doug Henderson MP remembers:
I've run 20 marathons, and I ran my first London Marathon before I was an MP and have run it several times since. It's a great experience.
London has by far the best crowd, they participate more than anywhere else.
I ran the Scottish National Marathon with nobody watching it.
Doug Henderson - second fastest MP ever
London and Paris are great marathons. It's also great fun in the build up to the race. I used to run for an athletics club until recently but now my knees are wrecked by running. I miss running dreadfully and wish I was running in the race on Sunday.
Whenever I smell the liniment, it gets the blood racing and sets the adrenaline going immediately. I can't watch the London Marathon on the telly any more as I miss it too much. I still think if I was fit enough, I could still probably do it.
Jogging and joshing
First Minister for Wales and former MP Rhodri Morgan is the fourth fastest with a time of 3hr 14min 44sec.
He remembers his experiences:
Whenever the London Marathon comes around I relive as though it was yesterday my own mini-participation in one of the great mass participation sporting events in the world.
What do I recall? Well I had done the Cardiff Marathon in 1985 in 3hrs 1min. I'd got elected in June 1987.
There was a fair sprinkling of new MPs in their 30s and 40s who enjoyed a healthy bit of jogging in the lunch hour before the serious business of the House of Commons got going at 2.30.
A half dozen of us would meet in the gents changing rooms and off we would set around St James Park and Green Park and on a Wednesday taking in the Serpentine as well - it was a great stress buster.
Rhodri Morgan salutes one of the world's great sporting events
If you wanted to make a good speech or ask a killer question that would have Maggie Thatcher breaking down at the despatch box on Tuesday or Thursday, first you had to get your brain free-wheeling to come up with the magic words by running five miles first.
The marathon itself passed in a blur. Passing through London Docklands, then at the commencement of the sharp downturn in property prices, at my marathon running pace enabled me to become an overnight property value expert.
There were even old genuine cockney family gatherings, with men in full dress Pearly King uniform outside pubs to remind you that the old East End was not just a figment of EastEnders scriptwriters.
Finishing in reasonably good shape was a fantastic relief as I was raising money from my fellow MPs to help one of my constituency youth clubs to go out to Kenya to build sustainable water tanks.
Wandering slightly dazed outside London County Hall, I was approached by a Dutch TV crew, who wanted to know whether we were all a little bit crazy in the UK, to think that raising money through sponsored runs like the London Marathon was a good way to fund our public services.
I didn't have the energy to come back at her with Marlon Brando's epic line from On The Waterfront - "You don't understand Charlie I coulda' bin a contender!"'
Conservative MP Bill Wiggin ran the marathon in 2002.
I'm not a very good runner but I never give up, so although I didn't do a very good time I really enjoyed it. People were incredibly supportive and I was able to raise a little bit of money for charity.
The marathon is a tremendous event, and I'd encourage anybody to get involved and enjoy the whole experience. I'm sure they'll be able to run it a bit quicker than I did.
MP Bill Wiggin - overtaken by a banana and rhino
In 1995 Conservative MP Bob Spink ran the seventh fastest time for an MP, coming in at 3hr 31min 15 sec.
I ran it for the first time in my mid-50s. As one gets older, one becomes aware of one's mortality and starts to take action to head off the inevitable decline!
My abiding memory is one of acute embarrassment when I was overtaken by a banana, a rhinoceros and a rugby team dressed as a school nativity play.
I trained for about three months and ran it with my son George Spink. My greatest joy was beating him, and I've never let him forget it!
I've run the Marathon three times now, but didn't do it this year because I thought there might be an election.
I'm hoping to run it in two year's time, after the next election, when I'll be 63.