I dont know about anti- religion - we tend not to habe parties that are anti anything. They tend to be more pro-something.
But id say labour and the lib dems hold many values that would be counter to traditional church values, as would the toriss on some things.
I dont remember any stories about politicians in this country coming out as atheist?
In fact the opposite is true of Blair, Tim Farron arguably lost his leadership due to the lampooning of his christian values, and new labour, probably the political party most in tune with the majority of Britain of any in my lifetime, famously 'didnt do god'.
And i doubt corbyn and his fellow socialists have much time for the opium of the masses.
Gay marriage, easing divorce laws, ending discrimination against gays, and many other things have all happened recently, against church wishes and lobbying.