Zhivago wrote:
They don't need the centre ground. They need to win votes back off SNP, Greens, and UKIP. Let the Lib Dems fight the Tories in the centre. And they need to get people who aren't politically engaged to become so, and vote for them. No one will become politically engaged to vote for a different shade of Tory.
May can't simply call an early election. Fixed Parliaments Bill from 2011 sees to that. Either a vote of no confidence needs to be called, which is risky, or 2/3rds of MPs must vote for an early general election. Neither will happen. The Tories want to wait at least until the boundary changes come into effect in order to gerrymander a better result, and Labour MPs will not vote for an election while their party is in disarray, as it is a risk to their cushy jobs.
They don't need the centre ground? The biggest change that'll come if Labour take many more votes on the left is that Labour will do much better in the constituencies which have a low voter turnout, but as Labor already hold more than 90% of those seats there are but a handful up for grabs that way. I don't especially like the FPP voting system we have, but it's the one you need to win under, and it's not going to happen by following Glorious Leader™
Also of course May can call an early election, I'm not sure she will given the crap fest created by Brexit, but t's hardly impossible to amend acts of parliament, so even supposing Labour wouldn't support a 2/3rds move and in the process announce even they don't think they're electable, then the government could just add to the statute that whilst a fixed term parliament remains as a consequence of the referendum result and a new PM being in place the 2020 election will be held in 2017 or 2018. It doesn't sound like they want to do that, but they might as well say they don't and then in the event Brexit talks start to drag or on the off chance Glorious Leader™ starts to prove annoying they've an option to call an early election