A record number of electors are applying for postal votes for the forthcoming general election, a newspaper survey has found.
Postal voting demand rose significantly in inner cities
A Guardian survey of 55 councils in 135 constituencies showed applications by post increased significantly in some areas, particularly in inner cities.
The figures come as there is increasing demand for urgent changes in the postal voting system to tackle fraud.
A High Court judge recently condemned the system in a vote rigging trial.
Richard Mawrey QC described it as "an open invitation to fraud" following a hearing involving allegations of fraud during last year's local elections in Birmingham.
The survey found the biggest increases in demand for postal voting were in Birmingham and Woking.
In Birmingham's 11 constituencies, more than 53,000 people have asked to vote by post, compared with 16,000 at the last election.
Meanwhile in Woking, 15,000 electors are demanding to vote by post when only 2,356 did in the previous election.
The Conservative Party also claimed last week that postal voting was in danger of bringing about a return to "18th Century fraud".
Shadow Commons leader Oliver Heald told MPs he had previously "cited examples of babies receiving ballot papers, heads of families filling them in for the whole family, employers threatening to sack staff unless they voted for a particular political party, and other worrying abuses".
The Electoral Commission said that the process needs to be tightened even though it believes postal voting should remain in place.