Pollsters are facing an independent inquiry into their accuracy after almost every survey during the election campaign underestimated the Conservatives' lead over Labour.

The British Polling Council, which acts as the association for opinion pollsters, will look into the causes of the "apparent bias" and make recommendations for future polls.

The move comes after political observers were shocked to see last night's exit poll showing the Tories comfortably ahead of Labour as the largest party, which was then followed by David Cameron's party winning an overall majority.

In the run up to polling day, almost every major national poll had predicted the race was neck and neck and too close to call.

The BPC, which counts all major UK pollsters among its members, said in a statement: "The final opinion polls before the election were clearly not as accurate as we would like, and the fact that all the pollsters underestimated the Conservative lead over Labour suggests that the methods that were used should be subject to careful, independent investigation.

"The British Polling Council, supported by the Market Research Society, is therefore setting up an independent inquiry to look into the possible causes of this apparent bias, and to make recommendations for future polling.

"We are pleased to announce that Professor Patrick Sturgis, who is Professor of Research Methodology and Director of the ESRC National Centre for Research Methods, has agreed to chair the inquiry, and will take the lead in setting its terms of reference.

"The membership of the inquiry will be announced in due course."

The pollsters have been criticised after offering almost universal predictions of a neck-and-neck race, a near-balanced parliament and a potential constitutional crisis following the General Election.

In the end, the Conservatives won an absolute majority, with 330 seats and Labour on 232, with one seat left to declare.

Chancellor George Osborne said the pollsters would face "a big post-mortem" while Michelle Harrison, of TNS, admitted it had been a "mixed night for the polling community".

Even the exit poll slightly miscalculated the results, predicting the Tories would end on 316 seats, with Labour on 239, the Lib Dems on 10 MPs, the SNP 58, Plaid Cymru four, Ukip two and the Greens two.