THE police have been called on to investigate whether or not letters sent out in David Cameron’s name by the Conservatives during the 2015 General Election broke election law.

In the latest episode in the row over the Tories’ election spending, Adrian Sanders, the former Liberal Democrat MP, told police in the West Country that mail-shots, sent out by the Conservatives, were not properly recorded as local election expenses and, thus, could have broken spending limits.

The Prime Minister’s party has hit back, stressing that the letters, which were signed by Mr Cameron, did not count as local campaign expenditure because they did not include the name of the local Tory candidate.

However, the letters repeatedly referred to Torbay, telling voters how important it was for them to support the Tories in the constituency.

One read: "The only way you can stop Ed Miliband and the SNP taking us back to square one is to vote Conservative here in Torbay."

Mr Sanders, who was MP for Torbay since 1997 but lost the seat to Tory Kevin Foster in last year’s General Election, said: "It is a specific targeted mailshot to a voter in a given constituency, saying vote for our candidate in that constituency. That has to be a local cost, not a national expense."

But a spokesman for the Conservatives argued: "Simply referring to the location where the elector lives does not promote any named candidate. The literature only promoted the national Conservative Party.”

He added: "Such literature was not a local election expense under the RPA [Representation of the People Act] regime as it was not connected with promoting the election of any candidate."

Earlier this week, Lincolnshire Police became the ninth force to reveal that it was investigating claims the Conservatives breached spending rules to win the election; the Prime Minister’s working Commons majority is just 17.

Tory HQ, which denies any deliberate wrongdoing, has handed information over to the elections watchdog, the Electoral Commission, which this week went to the High Court for an information disclosure order to get the documents.

The Conservative Party has been accused of recording the costs of activists, who were bussed into marginal seats in its election battle bus, under national spending limits rather than the much lower individual candidates' limits.

But the party, while it acknowledged that some accommodation for the activists was not properly registered, insisted that the bus tour was part of the national campaign organised by Tory HQ and so did not have to be recorded in individual constituency spending limits.