Sir Edward Leigh, the Conservative MP for Gainsborough, has written to the Home Secretary urging stronger action against people smuggling following the heightening situation at Calais in France.

In a letter to Theresa May, Sir Edward argued it is “clear” that illegal immigrants “are under the impression they will not be sent back” and that conditions for them in Britain are “quite advantageous”.

“Illegal immigrants must know that they will be arrested and held in custody without benefits until they are deported,” the Member of Parliament, re-elected this year with an increased majority, wrote.

“It is extremely unfair on those who play by the rules otherwise, and by appearing to give the impression that once here illegal immigrants are safe it only gives encouragement to human traffickers. Being weak is not kind.”

Sir Edward, who is a member of the Franco-British Council, also urged stronger cooperation between France and Britain in solving the crisis.

“Pressure must be brought to bear on the French government to take a more pro-active approach,” the MP said in his letter, adding that the French police are “well trained and well experienced” in dealing with disorder but that “we seem to be witnessing indecision and dithering on the part of the French authorities rather than productive and decisive action”.