The integrity of the EU single market and the preservation of freedom of movement will be non-negotiable in forthcoming talks on Britain’s post-Brexit relationship with its former partners, Michel Barnier has said.

The EU’s chief Brexit negotiator told the European Parliament there were very many more steps that need to be taken before a final Brexit deal is thrashed out with the UK, and made clear that the EU’s next priority is to consider a possible transition period, before turning to trade later.

His comments came as a leaked copy of the draft guidelines for future talks, obtained by a national newspaper suggested trade negotiations will not begin until March 2018, with work in the first three months of the year focusing on Theresa May’s request for an implementation period of about two years following the official date of Brexit in March 2019.

The document suggests that during this transitional period stretching to 2021, the UK will have to comply fully with EU trade policy and not strike its own deals, even though it is due to fall out of EU agreements with more than 50 other nations when it leaves in 2019, reported the FT.

Mr Barnier told MEPs in Strasbourg that if EU27 leaders agree to move Brexit negotiations on to their second phase, he will begin by hammering out the final wording of a Withdrawal Agreement.

He said this could be done fairly swiftly on the basis of the joint report agreed by the Prime Minister and European Commission president Jean-Claude Juncker last week.

Meanwhile, the European Council will also be looking at the definition of the transition period, including the question of the jurisdiction of the European Court of Justice, he said.

And, in an indication of further delay in the move to trade talks, he said: “There will be internal preparatory work that will need to be done with respect to our future relations with the UK.”

In these talks, he said, “there are points which are non-negotiable - integrity of the internal market, the ‘four freedoms’ (of movement for goods, services, capital and people) which are absolutely essential and fundamental to the foundation of the internal market”

Mr Barnier said the EU and UK have the shared objective to have good relations, but warned: “Obviously, we need to guarantee the integrity of the EU, which the UK has chosen to leave.”