UK’s Withdrawal from the EU

My right hon. Friend is being very generous in giving way. Before he moves on to the question of alternative arrangements, he and the Brexit Secretary are to be strongly congratulated on getting the European Union to accept the need to set up a taskforce of experienced officials on the European side and the UK side to work up the arrangements proposed by our working group. Will he guarantee that, once those proposals are accepted, there will be a commitment in the treaty that is legally binding and will commit the Government and the European Union to a definite and definitive date by which those arrangements will be implemented?