Cameron must veto this poisonous deal with Turkey before our response to the refugee crisis becomes immoral

EU leaders meet this week to discuss the refugee crisis and agree further measures to tackle it. More than ever, we need brave and principled leadership in the face of one of the greatest humanitarian challenges Europe has faced since the Second World War.

Yet, instead of working together to solve this crisis, it seems our increasingly desperate EU leaders look set to sign up to a deal with Turkey, which would raise the prospect of push-backs and compulsory expulsions of the thousands of refugees and migrants trafficked to Greece.

There are a number of good reasons why David Cameron should oppose this deal. First, as the UN and others have suggested, this planned agreement threatens to rip-up a number of basic humanitarian principles which Britain has signed up to and indeed promotes around the world.

For instance, collective expulsions of people seeking international protection are condemned by the EU's own Charter of Fundamental Rights. We know Turkey has failed to fully implement the Geneva Convention on refugees and has no functioning asylum policy. David Cameron would do well to re-read the international human rights agreements and principles Britain has committed to, before he signs on the dotted line in Brussels.

Second, given the deteriorating state of press freedoms and human rights in Turkey, this deal would risk sending vulnerable people who are in need of protection back to a country that is far from "safe". This is morally wrong and sets an unpalatable precedent, weakening our authority to fight for improvements in human rights standards globally.

Third, the policy won't work. Already we seeing new trafficking routes opening up to Italy and elsewhere. Instead of outsourcing our problems to Turkey, David Cameron should be taking the lead in fighting for a common EU approach, which is respectful of international human rights standards.

At the Liberal Democrat Spring conference last week, my party unanimously adopted a policy paper on Syria and the refugee crisis. One of our key demands is the call for safe and legal routes to be put in place, so that genuine asylum seekers can apply for humanitarian visas in the refugee camps themselves. This would remove the necessity for desperate families to risk everything, including their lives, for a place in a boat across to Greece.

There is no doubt about it - David Cameron has failed to respond adequately to this refugee crisis. We are a country with a proud history of welcoming those seeking protection. But by continuing to put his fear of Ukip ahead of doing what is right, he does our country a great disservice.

We only need to look to Canada to see what is possible. The new Liberal Prime Minister Justin Trudeau, horrified by the plight of so many Syrians on our side of the Atlantic, has delivered a programme which has resettled 25,000 refugees in Canada over a three month period. Despite the fact this crisis is in our own backyard, our prime minister had to be pushed to agree to take 20,000 over five years, well below what we are capable of.

Our continued inaction on the refugee crisis is a betrayal of Britain's history and our values. Instead of refusing to cooperate with our EU allies and turning his back on people fleeing war and terror, David Cameron should oppose this cynical deal and for once use our significant influence to fight for an EU wide response that is fair, just and respects the values we hold dear.