The UK is to send a team of experts to Greece to help root out economic migrants from the flow of refugees coming into Europe, allowing them to be sent back quicker.

The British officials will take part in the pilot fast-tracking deportation for those not thought to be refugees, in a bid to deter more people from coming.

It was announced ahead of today’s EU summit at which Theresa May has planned to discuss mass migration with leaders at the main session, while also having several further one-on-one meetings.

The gathering, which will also see Ukraine, Aleppo and Nato discussed, marks another occasion on which the 27 other EU leaders will at some point meet without the UK to discuss their approach to Brexit.

Ms May will send the team of 40 officials to Greece to take part in the pilot, while 110 have already been operating there.

A No 10 source said the purpose of the trial is to “determine the admissibility of asylum claims from Iraqi, Afghan and Eritrean nationals.”

She added: “Claims from those individuals are likely to be deemed inadmissible so rather than going into a certain type of asylum case flow, they go into a faster process which enables you to return them quicker.”

The source explained it was about increasing the “deterrent message”. More broadly, she said the Prime Minister will underline the “huge challenge” in dealing with mass migration and that “a practical, sustainable” way to approach the problem was needed that responded to humanitarian need, but also recognised the way domestic communities are responding.

Theresa May on immigration in conference speech

She added: “A failure to respond risks undermining our values and damaging the consent of our people to provide support to people that need it most.”

The Government will also advocate doing more with countries, such as Egypt, Jordan and Turkey, to help them better control their borders and tackling smugglers on the transit routes.

Ms May will hold talks with the outgoing President of the European Parliament Martin Schulz in the margins of the Brussels summit.

She will also meet Latvian Prime Minister Maris Kucinskis and Lithuanian President Dalia Grybauskaite, meaning that she will have held talks with leaders from all EU countries apart from Austria and Bulgaria by the time the summit starts.