The PM said the he had no plans to legislate, although he hinted ministers would not stand in the way of MPs attempting to introduce a backbench Bill.
Meanwhile, Home Secretary Theresa May echoed Culture Secretary Maria Miller earlier this week in suggesting a more limited reduction to 20 weeks.
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Thursday's weather for the west of the region
Thursday's weather for the east of the region
Foreign Office Minister Tobias Ellwood has been praised after attempting to save the life of the police officer killed in New Palace Yard.