Unregulated "Freedom of movement within the EU" was a parasitic economic policy designed to use poorer countries from Eastern Europe to make Western developed nations more competitive. It had the added ingredient of keeping wage rates here low and saving money on real re-training programmes.
It was a huge disgusting con and anti Socialist in every way imaginable.
No wonder then that it is cheered by the faux socialists on this forum. Jim says to his credit that it is the best bad option, but he is wrong, the best option is to walk away and watch Europe beg for a deal. The remoaners are Europe's fifth column and should be treated as such.
Corbyn argued against the EU all his political life he now ditches his principles in favour of the chance of transient power.
My advice to Mr Corbyn is watch your back, the people who tried to knife openly are now standing immediately behind you.