David Davis has fallen out with Oliver Robbins, the prime minister’s chief Brexit negotiator, over how much Britain can agree with Brussels in the next six months

David Davis is to send hundreds of civil servants to Brussels to begin negotiations on the UK’s future partnership with the EU after winning the first stage of a fraught internal battle over how to conduct the next stage of Brexit.

The Brexit secretary and Oliver Robbins, Theresa May’s chief Brexit negotiator, had a “significant” disagreement last week over how much Britain could realistically agree with Brussels between now and October.

This culminated in Mr Robbins delaying a letter that Mr Davis wanted to send out to select officials from across Whitehall to take part in the next phase of the negotiations. It was finally sent yesterday, although the row has worsened the already rocky relations between the two key figures running the Brexit negotiations.