Both Conservative and Labour in Parliament are agreed to leaving the EU (Andrew Marr Show on Sunday, asked both Keir Starmer and Philip Hammond about this.)
Firstly: They are both following the Party line. They have to.
Secondly: They are deliberately 'spinning' the result when, I'm sure, they both know very well that a huge part of Labour's success was a protest vote against the tory cuts and proposed privatisation of the NHS
Thirdly: In most constituencies, if you were against the tory cuts and wanted to cast a meaningful vote, one had no choice but to vote Labour; it was too risky to hope for a massive Liberal surge. (sorry, varian)
Essentially, for Remainers, it's like living in a nightmarish Brexit dictatorship with the views of almost half the voters not being taken into consideration..