She is the leader of the Women’s Equality party (WEP), a new political force committed to furthering the cause of gender equality, but which has yet to make inroads electorally.

He is a Tory MP who tried to derail a bill to protect women against violence, and told a conference hosted by an anti-feminism party that “feminist zealots really do want women to have their cake and eat it”.

Now, in what is likely to be one of the most fascinating clashes of the general election, Sophie Walker and Philip Davies are to face off on the campaign trail as other opposition parties consider giving her a free run in her attempt to unseat the Shipley Conservative MP.

The developments in the West Yorkshire constituency come as attempts to engineer a broader “progressive alliance” gather steam. On Monday the leftwing pressure group Compass will launch a website to help maximise the anti-Conservative vote in constituencies around the country, and bring together activists from the three main opposition parties in a new political movement.

Walker, a journalist who became the WEP’s inaugural leader in 2015 and has been at the forefront of its campaigns for equal representation and pay in working life, said: “Philip Davies basically is a sexist misogynist who puts his own ego ahead of his constituents. His anti-equality agenda in Westminster threatens the rights and freedoms not just of women but also people with disabilities, BAME (black, Asian, and minority ethnic) and LGBT+ communities. I think that Shipley deserves an MP who will prioritise representing them and the issues that are important to their constituency, rather than using parliament as a stage to play out attention-seeking performances.”

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Davies said: “I have consistently asked Sophie Walker to quote just one thing I have ever said which has asked for a woman to be treated less favourably than a man, and she hasn’t been able to find even one quote from the 12 years I have spent in parliament.

“I would very much welcome Ms Walker parachuting herself into Shipley as a candidate with her extreme politically correct agenda of positive discrimination and quotas, and am very happy to let the good people of the Shipley constituency decide who they want to represent them.”

The Green party approached the WEP with the offer to stand aside, according to local Green activists in Shipley, who have yet to rubberstamp the idea but are supportive of it in theory. The idea has not so far been floated widely among local Liberal Democrats, who meet on Thursday, but there is strong support already among some officials.

However, while the idea of Walker’s candidature has been discussed by WEP and Labour members of Shipley Feminist Zealots, a local group, some Labour members are eager to field a candidate. Local chairman Joe Wheatley said that Labour had shown itself as the “most effective” opposition to Davies, who racked up a 9,624-vote majority over his Labour runner-up in 2015.

Why the Women’s Equality party may hand Philip Davies MP a win in Shipley | Robyn Vinter Read more

The Brexit-supporting MP will be boosted in a constituency that mirrored the referendum’s national result. Walker, a Remain supporter, wants an “equality impact assessment” of any final Brexit deal, and the chance for MPs to vote it down if necessary.

The constituency is not the only one where moves by opposition parties to work together are under way. In the west London marginal of Ealing Central and Acton, the Labour incumbent, Rupa Huq, was told on Saturday by local Green activists that they will give her a free run as she seeks to defend her wafer-thin majority of 274 from a Tory challenge.

Echoing the view of Green party leaders Caroline Lucas and Jonathan Bartley that the three main opposition parties should stand aside for each other in some seats, Green members have decided to support Huq because she has met three conditions: she broke a Labour whip to vote against the triggering of article 50, opposed Heathrow airport expansion, and supports voting reform.

Huq said: “The local Green party knows that I am a resolute Remainer and that, if necessary, I will continue to break any and all whips to fight for the UK to stay in the EU.” The seat’s voters last year backed remaining in the EU by 72%.

“In these perilous times it is vital that we work together to oppose this reckless surge towards Brexit,” she added, warning that the Liberal Democrats would risk splitting the Remain vote if they did not follow the example of the Greens.

While the leaderships of the main opposition parties have not endorsed nationwide pacts, a concerted drive to marshall anti-Tory votes will kick off on Monday with the launch of a new political movement, the Progressive Alliance. Labour, Liberal Democrat and Green activists will sit in a central London “war room” and plan how to win dozens of Tory seats where the other parties achieved combined majorities in 2015.

In particular, strategists are zeroing in on clusters of seats such as East Sussex and Brighton, where tactical voting could have a significant impact. Rallies are also being organised in key cities where the movement believes that alliance politics can make a difference.

Scottish National party and WEP activists are also involved in the new movement, which has been endorsed by Lucas, the Green MP for Brighton Pavilion, and the Norwich South MP and possible Labour leadership contender, Clive Lewis. The support of Lib Dem and Green voters could be crucial to Lewis’s hopes of retaining his seat in a city where the Remain vote was 56.2%.

“Labour has always benefited from political alliances – the last time was 1997, when an under-the-radar deal with the Liberal Democrats not to contest key seats crushed the Tories,” he said. “This is not just about stemming and reversing the blue tide by campaigning and voting smart, but doing politics differently in a more collaborative way.”

Lucas said: “While the Labour and Lib Dem leadership are lagging behind their own members and the general public on electoral alliances, it’s great to see people taking things into their own hands.”

Neal Lawson, chair of Compass, said: “If we don’t want to wake up to Tory domination for decades on 9 June, we have to start fighting them and not each other. It will be alliance or annihilation.”