Conservative activists urge PM to extend border controls
30 December 2013 Last updated at 10:45 GMT
Ninety senior Conservative activists have urged David Cameron not to lift border controls on Bulgarian and Romanian migrants on 1 January.
In a letter to the PM, they argue he could use a clause in EU law to prevent a "hugely disruptive and destabilising wave of mass immigration".
It allows countries to continue with border controls if they have "serious labour market disturbances", they add.
Iain Watson explains.