Five party leaders from Ukip, the Lib Dems, Greens, SNP and Plaid Cymru have handed in a petition with half a million signatories to Downing Street.
The party leaders, who put aside their differences from across the political spectrum, say Britain's voting system is unfair.
They may have a point: votes cast in the election seem to have very little bearing on its result.
The Conservatives gained 36.9% of the vote and get to run the whole country - similar strange results happened under Tony Blair, too.
Ukip, which scored a breakthrough 12.6% of the vote, only won a single seat - 0.15% of the 650 seats in parliament, to be precise.
The Green Party won well over a million votes and got one seat.
As long as the voting system stays unchanged, Labour or the Tories will likely be able to keep their opponents at bay.