THE prospect of a tough Brexit road ahead has been signalled by Brussels as a draft European Parliament resolution makes clear that MEPs should reject Theresa May’s plan for a simultaneous deal on trade alongside one on withdrawal.

The details of the draft resolution, to be debated next week, came as Donald Tusk, the President of the European Council of leaders, expressed sadness at Britain’s departure, saying: "We already miss you. Thank you and goodbye."

But he also made clear that, paradoxically, something positive had come out of Brexit. “It has made us, the community of 27, more determined and more united than before,” he declared.

Antonio Tajani, the President of the European Parliament, warned that Brexit without a deal with the EU27 would be a "catastrophe" for the UK.

He made clear that it would not be possible to secure a deal unless there was an acceptable agreement on the status of EU nationals resident in the UK and British nationals living on the continent; something the Prime Minister has made clear she wants early agreement on.

Describing Brexit as an "unprecedented and regrettable event", the European parliamentary resolution calls for the process to be arranged "in an orderly fashion so as not to negatively affect the EU, its citizens and the process of European integration".

It states it is the "duty" of the EU27 "to act in unity in defence of the EU's interests and its integrity".

The document, drawn up by leaders of the main political groupings in Strasbourg and expected to be adopted, warns "a state leaving the Union cannot enjoy similar benefits as an EU member state" and makes clear the Parliament "will not consent to any agreement that would contradict this".

But it holds out hope for Remainers that the UK could revoke its notification of Article 50, effectively halting the Brexit process and allowing continued EU membership.

Yet it warns this would be "subject to conditions set by all EU27 so they cannot be used as a procedural device or abused in an attempt to improve the actual terms of the United Kingdom's membership".

The draft resolution makes clear that a new trade deal between the UK and the remaining EU "can only be concluded once the United Kingdom has withdrawn from the EU".

Guy Verhofstadt, the European Parliament’s chief negotiator, stressed that Britain should not “go behind our backs” to do a trade deal with another country outside the EU while the talks were ongoing. He also warned EU member states, which might be "tempted" to do their own deals with the UK.

The draft resolution notes that any attempt by Britain to negotiate its own free trade deals with outside countries before Brexit result in an end to the talks on a UK-EU deal.

It states continued membership of the single market and European Economic Area would be the "optimal" solution for both the UK and the remaining EU but says this "is not possible as long as the UK Government maintains its objections to the four freedoms and the jurisdiction of the Court of Justice of the EU, refuses to make a general contribution to the EU budget and wants to conduct its own trade policy".

Instead, it suggests the UK could be offered an "association" status similar to that enjoyed by Ukraine.

The document says any transitional agreement to tide over the period before a trade deal is put in place should last no more than three years after the expected date of Brexit in 2019, raising the prospect that a UK-EU trade deal might not be sealed until 2022.

The significance of the draft resolution is that the European Parliament effectively holds a veto on any exit deal as it must be approved by a majority of MEPs in a vote after having first received the assent of a qualified majority of leaders in the European Council.

A trade deal would have to be separately approved by the European Parliament and is likely also to require the support of 27 national parliaments and a number of regional assemblies across the remaining EU.

In a sign Brussels is set to insist on the payment of a "divorce bill" estimated at £50 billion, the resolution states the UK must honour "all its legal, financial and budgetary obligations, including commitments...falling due up to and after the date of its withdrawal".

Mr Verhofstadt, the former Belgian Prime Minister, echoed the point, and also stressed that any deal with the EU could not be better for the UK than full membership.

"That is not a question of revenge, that is not a question of punishment, that is the logic of the European Union, of the European treaties, of the European project," he declared.

The draft resolution also states there can be no special deal for the City of London offering UK-based firms "preferential access to the single market and/or the customs union".

And it warns Britain cannot impose a cut-off date for EU nationals to establish residency before the Brexit process is complete, stating "any degradation of the rights of residency before the date of withdrawal" is against EU law.

Labour MP Chuka Umunna, a leading supporter of the Open Britain group, said even before Mrs May had finished her Commons statement the first leak from Europe had “blown a hole in the Government's complacent vision of Brexit”.

He added: "It lays bare the risks for Britain that lie ahead in the negotiations, not least the difficulties facing the Government in trying to deliver on their pledge of getting a trade deal that delivers the 'exact same benefits' as we have today. Today is the start of the Government's rosy rhetoric colliding with reality.”