Trusted by Theresa May, berated by Brexiters - Olly Robbins is the quite possibly the most powerful man in Westminster you’ve never heard of.
At six foot three inches, Mr Robbins is tall in stature but low in public profile - a civil servant who has worked for every Prime Minister since Tony Blair, rising to become Mrs May's Europe advisor and chief Brexit negotiator - tasked with taking trips back and fourth to Brussels to secure Britain's negotiated exit from the European Union.
Indeed, he has been described by some in Whitehall as ‘the real Brexit Secretary'.
Born in 1975, his is a well-trodden path to public service: public schoolboy, Oxford graduate - Olly Robbins' degree in Politics, Philosophy and Economics took him straight into the Treasury in 1996.
A decade later he was poached by Tony Blair to become his Principal Private Secretary, before moving to the Cabinet Office under Gordon Brown. He was David Cameron's Deputy National Security Adviser, and worked in the Home Office while Theresa May was Home Secretary.
After the Brexit vote in 2016, Mr Robbins moved to the Department for Exiting the European Union as Permanent Secretary before finally making the move to the Cabinet Office as the PM's closest Brexit confidant and negotiator-in-chief in the civil service, in a role created just for him, despite having little experience negotiating with the EU.
From there, he runs the day-to-day Brexit negotiations. The government sets the red lines, the ambitions, the political agenda - the civil servants try to make it happen.
Mr Robbins has spent the last two years trying to negotiate a deal on behalf on the British state - locked in long discussions with his counterparts in Brussels, discussions which ultimately led to November's Withdrawal Agreement and Political Declaration, and with it the much-despised Irish backstop.
As we know Tory Brexiters can't stand that deal (they emphatically voted it down in Parliament) and in recent weeks they've turned their fire on the man who led the negotiations.
Iain Duncan Smith has suggested Mr Robbins be replaced; Mark Francois said he should "should go to the Tower" for the way he has conducted the negotiations, claiming the Brexit negotiator was pro-EU and doesn't want the UK to leave.
Mrs May's refusal to change her civil service team in the wake of that heavy defeat last month, sticking by Mr Robbins as she attempts to renegotiate her deal, has further fueled tensions.
It is rare for civil servants to face such public criticism, and as civil servants are not permitted to give media interviews, it is even more rare to hear their private views.