Yoichi Masuzoe claimed in an interview with a men's magazine that women were not able to make critical decisions when they having a period because they are 'not normal'.

A Twitter campaign called 'the association of women who will not have sex with men who vote for Masuzoe' has gained 3,000 followers since it launched last week.

However, despite their best efforts, the former health minister backed by Japan's ruling party, won Tokyo's gubernatorial election on Sunday, defeating two candidates who had promised to end nuclear power.

The anonymous group founders say in their profile: 'We have stood up to prevent Mr Masuzoe, who makes such insulting remarks against women [from being elected] … We won't have sex with men who will vote for Mr Masuzoe.'

In the 1989 interview he said women were irrational because of their menstrual cycle.

He said: 'Women are not normal when they are having a period … You can't possibly let them make critical decisions about the country [during their period] such as whether or not to go to war.'

A second petition website was also launched on Wednesday, by a group of women trying to stop him from becoming governor of Tokyo, attracting 75,000 hits a day, the Guardian reports.

Masuzoe's victory was declared in exit polls on public broadcaster NHK within minutes after voting closed.

Masuzoe, 65, appeared smiling before cameras, with his supporters shouting 'Banzai,' and promised to make Tokyo 'the No. 1 city in the world.'

The ballot was widely seen as a test for Japan's public opinion on atomic power in a nation shaken by the Fukushima nuclear disaster.

But the anti-nuclear camp was divided between two candidates — former Prime Minister Morihiro Hosokawa and human-rights lawyer Kenji Utsunomiya.

Masuzoe garnered about 30 percent of the vote, according to NHK exit polls.

Hosokawa and Utsunomiya got about 20 percent each, indicating that if the anti-nuclear vote had been united, a win by either might have been possible.

Official vote tallies were not expected until Monday.