Pogs in regard to your post @ 13:36 today (21/06/19) then Theresa May did offer the Labour Party guarantees on employee rights etc, but she was not prepared to write those guarantees into new legislation. Therefore, the Labour party could not accept Mays so-called "guarantees, and the negotiations broke down.
However, as has been stated on so many occasions on this forum, the Labour Party are not the party of Government in the United Kingdom at this time. That accolade is held by the Tory party and had all that parties MPs along with the paid for buttressing of the Northern Ireland Democratic Unionist Party been in support of Theresa May's withdrawal agreement, then that agreement would have been passed by the House of Commons, and Britain would now have left the European Union.
It is this Tory government that is solely responsible for the crisis that Britain now faces, with the Labour Party being only one the parties of opposition in our Parliament. Therefore, those opposition parties hold no overall responsibility for the current debacle, however much many on this forum try to place blame on them.