Labour is currently on a little over 20% in the opinion polls. Were there to be an early election the party would have no clear answer to the question would you take us out of the EU. In Parliament Labour voted to send in our Article 50 notice letter. It then opposed the EU’s Withdrawal Treaty and now opposes the alternative of leaving without signing that Treaty. Why on earth would they want an election in such circumstances? So far they have been unable to clarify how they would negotiate a better Brexit , what it would look like and why the EU would consent. It leaves them refusing to accept departure with the WA or without it, and refusing to admit they want to revoke Article 50 altogether.
Any election before the UK has left the EU would push many Remain supporting former Labour voters to vote Green or Lib Dem as they offer a second referendum and oppose Brexit. Leave voting former Labour voters would be tempted to vote for the Brexit party or the Conservatives to get the Brexit they voted for in the referendum which Labour promised to support in the last General election. As in the recent European election Labour would be likely to be badly squeezed. The Conservatives are recovering in the polls now the new PM says we will definitely leave on 31 October, after the crash under Mrs May with her disastrous delay.
Labour now complains that if they could get a majority in the Commons to defeat the government twice on a motion of no confidence within 14 days to trigger an election, Brexit would happen anyway during the election. Of course it would, as the law they helped pass to send our withdrawal letter ensures that we leave. The irony is Labour has much better prospects in an election once we have left and Brexit is behind us. The intense muddle of their current Brexit approach is losing them support from both sides of the argument, and driving people to a clear Remain party or a clear Leave party.
Were Labour to table and win a confidence vote in September they would need to do it twice to conform with the Fixed Term Parliament Act. It is difficult for them to do this in time for an election prior to the 31 October. The honest way to stop us leaving would be to propose that Parliament revokes Article 50, which we know the EU would accept. They will not do that as they know there is no majority in the Commons to reverse the Withdrawal legislation and to tear up the Manifesto promises of both Labour and Conservative from the 2017 election.