Conservatives admit 2015 election expenses 'error'
The Conservatives have admitted failing to declare £38,000 of general election expenses.
The party blamed an "administrative error" for failing to register the accommodation costs of activists involved in the Battlebus 2015 operation.
The admission follows a Channel 4 investigation.
A Conservative spokesman said the party had already brought the error to the attention of the Electoral Commission.
The Tories insisted the Battlebus operation was part of the national campaign organised by Conservative Campaign HQ and, as such, the expenditure did not form part of the spending by individual candidates.
But Channel 4 said its investigation suggested the operation was focused at a local level, so should have been declared as such.
An Electoral Commission spokeswoman said: "The commission is currently conducting an investigation into the Conservative Party's 2015 General Election spending return and will consider carefully any new allegations that are raised as part of the Channel 4 news programme.
"In line with the commission's enforcement policy, the commission does not comment on ongoing investigations, as to do so may hinder the conduct of the investigation."
The Conservative Party issued a statement saying its activists were campaigning "across the country for the return of a Conservative government" and, as such, their activities were regarded as national not local expenditure.
"As is apparent from our national return, the party declared expenditure related to our CCHQ-organised Battlebus," it said.
"However, due to administrative error it omitted to declare the accommodation costs of those using the vehicles. This is something we have already brought to the attention of the Electoral Commission in order to amend the return."
"The party always took the view that our national Battlebus, a highly-publicised campaign activity, was part of the national return - and we would have no reason not to declare it as such, given that the party was some millions below the national spending threshold. Other political parties ran similar vehicles which visited different parliamentary constituencies as part of their national campaigning."