Britain will suffer outside the EU deal-making room

This is the most important European summit for a generation and its outcome is looking increasingly worrying for the UK.

We have warned consistently that an isolated David Cameron has been on the sidelines of Europe for months, out of touch abroad in the same way as he is out of touch at home. He has been hamstrung by the divisions in his own party, imprisoned by the Eurosceptics and his failure to confront his party over the last five years.

There are simple lessons to learn from the Prime Minister's failure last night. If you get out of the deal-making room as he has done over the last year, you end up losing influence. Having no allies is a sign of weakness, not of strength.

There are serious questions to answer.

We need an assurance that Mr Cameron has not allowed a deal to emerge that means 25 of the 27 will rewrite the rules of the European economy without the UK in the room. Will the signatories to the new treaty be able to impose economic barriers to those in the EU but outside the new treaty?

Will this new treaty be run by the EU institutions, and be enforceable in EU courts? Will the UK have a seat at the table when vital economic decisions are taken?

Have we now got the two-speed Europe Britain has always opposed, but without any of the safeguards the Prime Minister promised to deliver?

And for all the talk of treaty change, where is the plan for growth and jobs that should have been the other focus of this EU summit?

The list of questions are long and the answers will affect the jobs and lives of all British people.

We should have ensured an agreement that reflected a simple principle: decisions affecting all 27 members of the European Union must be made by the 27.

There is clearly a case for deeper cooperation by the eurozone countries, but at the heart of British foreign policy, at the heart of our commitment to the EU, must be a basic principle that the future of the single market and future European cooperation is shaped by all the countries who are part of it, not just those who share the single currency.

The lesson for the Prime Minister is that to treat Europe as merely an excuse for the failure of your economic policy, or a problem to be negotiated with your backbenchers, serves us ill.

It makes us marginal to the big decisions on Europe. It is no way to run a foreign policy. And it lets down our country.