By political editor Paul Francis

Ashford MP Damian Green and Prime Minister Gordon Brown have clashed over immigration policy during a boisterous last session of Prime Minister's question time before polling day.

Mr Green, the Conservative shadow immigration minister, tackled the PM over statistics revealing the number of UK private sector workers in employment was "several hundred thousands" lower than in 1997, when Labour came to power.

The MP asked if Mr Brown recalled making his commitment to ensure there were British jobs for British workers and what he made of the latest official figures, which appeared to suggest that pledge had not been met.

Mr Brown replied that the number of migrants now arriving in the UK had fallen and defended his party's policy of adopting the Australian points-based system for migrants.

"Net migration has fallen because of the action we have taken and there are more people here getting the jobs they need and that are available."

He went on: "I think the Conservative party should think twice about their policy on quotas. Their policy on quotas without giving a number would do great damage to British business."

The last PMQs before May 6 was marked by noisy exchanges between Mr Brown and Mr Cameron over the Government's plans to raise National Insurance tax contributions.

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