The blueprint for reform of the EU is a "fair" settlement for Britain, the president of the European Commission has said.

Jean-Claude Juncker said plans for an emergency brake would address the "record numbers" of EU citizens that moved to the UK after the Government failed to apply transitional measures more than decade ago.

It would last for a "period of up to four years" and would apply in "exceptional cases", he said.

"The duration of the mechanism will be limited in time. That is a crucial characteristic of a safeguard mechanism necessary in order to make it compatible with the treaties."

He added: "In effect we will enable the United Kingdom to use the mechanism to address the consequences of that decision."

Mr Juncker said he had worked hard with Prime Minister David Cameron to shape the deal and the Commission supports the proposals.

He said: "The settlement that has been proposed is fair for the UK and fair for the other 27 member states."

The UK already benefits from more opt-outs and protocols than any other member state, he told the European Parliament.

"This is why, as a matter of law and a matter of fact, the concept of ever closer union has already assumed a different meaning in its case," he added.

"The settlement recognises this. It recognises that if the United Kingdom considered that it is now at the limits of its level of integration then that is fine. At the same time, it makes clear that other member states can move towards a deeper degree of integration as they see fit.

"In this way, we have addressed the Prime Minister's concern, while respecting the treaties."

Mr Juncker said it was legitimate for member states outside the eurozone not to have financial responsibility for measures taken to shore up the currency bloc.

He added: "The euro remains the currency of the European Union, the parliament remains the parliament of the union as a whole."

Negotiations with the UK, along with the refugee crisis, have allowed commentators to claim there was a "pyschodrama" unfolding where Europe is "falling apart little by little", he added.

Ukip leader Nigel Farage said the proposals did not secure treaty change, failed to return powers and did not give Britain any control over its borders.

He told MEPs: "In fact, it was hardly worth the wait. It is really rather pathetic."

Mr Farage said the Prime Minister would be forced into a "humiliating" round of Oliver Twist-style begging at the European Council meeting later this month where he will ask other leaders "Please can we have some more concessions?"

"I'm certain of one thing - he won't get another thing," he said.

The Ukip leader added: "All we have to do is recognise that, while the politicians and the big banks and the big businesses will in this referendum defend their own vested self-interests, it is people power that will win this referendum."

French National Front leader Marine le Pen dismissed the renegotiation as "just theatre", telling the European Parliament: "I don't think anyone is being taken in by this masquerade that the Brits can improve what's happening in the EU and stay in. It simply isn't going to happen."

Democratic Ulster Party MEP Diane Dodds said Mr Cameron's negotiations were "little more than a choreographed talks process, a faux battle, a smoke-and-mirrors charade that has resulted in little more than the status quo, a failure by our Prime Minister to stand up for our United Kingdom".

But German MEP Hans-Olaf Henkel, a member of the Tories' ECR grouping in the European Parliament, warned that if Britain left, "the EU would slowly but surely demise" and insisted that the reform package was "not only good for the UK but good for Europe".

And the sole Liberal Democrat MEP, Catherine Bearder, said: "Britain can only play a bigger role in the world by playing a bigger role in the EU ... Being part of the EU is better for Britain under all circumstances - better for our prosperity, our security and our environment."

Independent MEP Janice Atkinson, who used to represent Ukip, said the Prime Minister had been given "absolutely nothing".

"It's Cam sham and Labour will keep the white flag flying along with the Greens and the remaining Lib Dem," she said.

"The British public knows that this was a Chamberlain moment and so did the British newspapers."

She added: "Crucially, our borders will remain open to migrants and terrorists.

"The truth is Cameron got pretty much what he asked for - absolutely nothing."

Former Belgian prime minister Guy Verhofstadt said the UK would be a "dwarf" if it left the European Union.

Mr Verhofstadt, president of the Alliance of Liberals and Democrats for Europe, said: "I think it would be a huge mistake if Britain would leave the European Union, not so much economically ... most of all geopolitically.

"I think Britain without Europe, okay, it's a dwarf - let's be honest. We Belgians, we know that we are dwarfs, but maybe they are going to know it also.

"On the other hand, Europe without Great Britain doesn't count, it is not a counterweight against China, against Russia, against the United States."

He said a divided Europe would be welcomed by Russian president Vladimir Putin.

"Mr Farage and Mr Putin, they are those who want a divided Europe," he said.