I count 306 seats where Labour are 1st and the Conservatives 2nd, or Conservatives 1st and Labour 2nd.
In the other 326 seats, either the Lib Dems, Reform, Greens, SNP, Plaid Cymru or independents are a top two party. Where most voters live, the traditional Labour vs Conservative debate is no longer the relevant one.
On Merseyside the Greens are second in the majority of constituencies, the Tories are often fifth. It’s been like that for a while I think.
The 99 seats where the Lib Dems are top-two are the really interesting ones here because a) most of these seats are now ones they actually hold rather than ones where they’re runners up, and b) their main challenger in these (typically middle-class Southern) seats is almost always the Tories. The Lib Dems winning 72 seats this time is an enormous part of why the Tories had a record-breaking bad night as opposed to just a regular bad one, and their ability to sustain this next time will be key to keeping the Tories out of government in future.
For the other parties (e.g. Greens are top-two in 43, mostly in big cities; Reform in 103, mostly white working-class Brexit areas), they’re almost always the runner-up party (usually by quite a big margin) behind Labour.