He could become PM with LAB getting fewer votes and seats
A big advantage for Starmer over Johnson at the next general election is that he is in with a good chance of becoming PM if the Tories lose their majority. This would be the case even if LAB has fewer seats. The converse is that Johnson’s Tories almost certainly have to win an overall majority of Commons seats to retain power.
This is all because if Boris fails to retain an overall majority he would find real problems trying to create a grouping or some sort of support that would keep him in power. For over the last 11 years the blue team has managed to burn its bridges with the two groupings who previously they could possibly have looked to – the LDs and the DUP.
It will be recalled that it was the former who enabled Cameron to become PM at GE2010 and the latter who came to help TMay’s government remain in power after losing the Tory majority at GE2017. Whether the DUP would do the same again for a Johnson government after the way that Brexit has been resolved for Northern Ireland is a moot point. It certainly could not be relied on.
What Starmer needs is for the Conservatives to lose their majority. Excluding the Sinn Fein MPs who never take their seats that means the Tories losing 47 or more of the seats won in December 2019.
Possible Tory losses break down into three main groupings only one of them LAB-CON battles.
Firstly there is Scotland where the party lost more than half its MPs at the last election and only now has six. If the SNP remain strong that could be almost wiped out.
Secondly a significant number of the Tory seats with very small majorities are against the LDs who it will be recalled came out of GE2019 with one fewer seat even though they increased their national vote share by 4.6%. My guess is that Starmer’s LAB, unlike Corbyn’s party last time, will only make token efforts in these seats because it is clearly in the Labour interest for the Tories to lose seats.
Thirdly there are so-called red wall some of seats which could flip back to the party because LAB will not be encumbered with a leader who is electoral poison as Mr. Corbyn proved to be in December 2019.
Given the SNP dominance in the former LAB stronghold of Scotland which delivered 41 MPs at GE2010 it is hard to see Starmer’s LAB winning a majority. But if there are sufficient CON losses LAB could be in a position to lead a minority government.