Prime Minister Attorney General Geoffrey Cox has become a key figure in seeking a legally watertight solution to the Irish kickback problem.
He has been accused of drafting new proposals for a "revision mechanism" in the Brexit withdrawal agreement in order to allow Britain to withdraw from any kind of backstop arrangements.
A frozen lawyer ran through the cabinet behind legal arguments behind a backstop aimed at avoiding setting a "hard border" in Ireland if negotiations on trade in the future trade failed.
He told them that there is a legitimate "frequency" of what is possible to prevent the United Kingdom from being trapped in "limbo".
One option is that the review mechanism includes an independent body that decides whether the trade negotiations have failed.
He has understood that he is in favor of the plan to keep the UK as a counterbalance to the customs union and leave it only to the EU's approval.
Mr Cox has only been in the cabinet since July, and he was a little known even in the Tory circles until the last party party party had a speech.
However, Theresa May has gained great confidence in her and has added her to the Cabinet Committee, which oversees the Brexit negotiations.
He is now working with Brexit Secretary, Dominic Raab and his European Counselor, Olly Robbins, to finalize the details of the check mechanism.
His altitude has also been designed to send a calming message to Brexiteers concerned that Mr May could prepare to make a concession too far in Brussels.