BRITAIN’S three female party leaders united yesterday to launch an alliance against Westminster austerity — but ruled out speaking for each other in TV election debates.

Scottish First Minister Nicola Sturgeon set out her “new approach to politics” in Parliament alongside Plaid Cymru’s Leanne Wood and Green Party leader Natalie Bennett.

Ms Sturgeon — dubbed the most powerful woman in British politics — was in London to meet Tory PM David Cameron for the first time since taking the reins from Alex Salmond.

Polls suggest that her party’s post-referendum surge could see the nationalist and Green group grow to more than 30 MPs after the election.

The trio made clear that the cost of their support for any minority Labour government would be an end to austerity and Trident nuclear weapons.

Slamming Chancellor George Osborne’s Autumn Statement, Ms Sturgeon said it was possible to balance the books without reducing spending to levels last seen in the 1930s.

“I lead a government that has for the past seven years balanced its books every year,” she told a joint press conference.

“But the Tories have slipped over from responsible management of the deficit and debt to an ideological cutting of the state and I don’t accept that is the right way to go.”

Green leader Ms Bennett said Britain’s economic debate urgently needed a “human dimension” that focused on the “extreme misery” caused by Con-Dem cuts.

Ms Wood too earlier told the BBC’s Daily Politics show that their alliance presented an “alternative to the four shades of Westminster grey.”

She said it was a “matter of democracy” that their views were heard in the pre-election TV debates.

But Ms Sturgeon rejected

a suggestion that one of the trio could represent the views of all three in the debates.

She also appeared to rule out the trio presenting Labour with a joint list of demands should Ed Miliband’s party fall short of an overall majority.

“Leanne and I are very close politically and our parties have been for a long time but we don’t share the same views on everything,” said Ms Sturgeon.

“I don’t anticipate us negotiating as a bloc but we’ll seek to make common cause where we can.”