Annual net migration has soared well above 100,000 in almost every year since the Government relaxed border controls with a string of new EU member nations in Eastern Europe in 2004.
Official figures in May showed the number had hit 330,000 over the last year, the second highest figure on record.
It was Mr Cameron who committed the Tories to cutting annual net migration “from the hundreds of thousands to the tens of thousands” when opposition leader in the run up to the 2010 general election.
The figure was based on figures routine seen in the country before EU free movement rules were extended into Eastern Europe.
Mr Cameron’s coalition government in the last parliament failed to deliver the target, with Tories at the time blaming their Lib Dem coalition partners for hampering moves to restrict immigration.
At the last general election, the Tory manifesto insisted the 100,000 maximum was “right.”
“That ambition remains the right one,” the manifesto said.