As Prof. John Curtice observes (after his latest polling), showing around 80% of likely labour voters are pro-EU: 

'Labour does have to realise it will find itself back in office off the back of an electorate that is three-to-one in favour of joining the EU'.

Whether or not this means #Labour may be thinking about how to re-engage with the #EU, rejoining, of course, is not something we can just wish to happen, the EU would need to agree & that willingness is hardly a foregone conclusion!