Eddie Izzard celebrated completing 43 marathons in 52 days by predicting today that he would run for parliament in Westminster or Brussels within the next 15 years.

Having closed out his 1,100-mile, seven-week slog for charity in London yesterday, the 47-year-old talked of his future plans as he went to Downing Street to meet Gordon and Sarah Brown and David Miliband, the foreign secretary.

The self-styled "action transvestite", who was raising money for Sports Relief, put his success down to his "relentlessness", saying "I've said I will stand as an MP or MEP at some stage, in 10 to 15 years. I like to make long announcements. But at the moment, I've spent so long trying to get my career going [that] I don't want to throw it away."

"I feel really good. My legs hurt, my body hurts, I'm very tired. I lost my toenails, had blisters and stuff, but to finish – it's kind of like science fiction in a way," said Izzard, who starts a 44-date tour next month in his more familiar role as a standup comic.

He said he wouldn't stop running. "I do have to wind down but I want to keep a couple of long runs going a week. I don't want to throw it all away."

Izzard has already raised more than £200,000 after completing a programme that sometimes involved running distances of 31 miles a day. He trained for just five weeks beforehand and attributed his success to a victory of mind over matter.

"My analogy was world war two. They all did amazing things that they were not planning to do. They became commandos and they shot anti-aircraft batteries, and if you imagine in your head you are going to do this extreme thing then you do it."