Shadow Home Secretary Yvette Cooper will deliver a speech today on immigration controls.
She said immigration has "got to be controlled."
Speaking about the issues of mass immigration from eastern Europe, Ms Cooper said, we must "deal with some of the exploitation of migrant workers who have come to this country and ended up not being paid the minimum wage."
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The move comes amid a motion of no confidence that was tabled against Labour leader Jeremy Corbyn.
The first anniversary of the Sousse terrorist attack - which left 30 Britons dead - will be marked by families of the victims on Sunday.
Since Friday's EU result, the Liberal Democrats have recorded thousands of voters signing up to become members.