It is a controversy that has largely been overlooked by the national media – but four of our region’s MPs are currently under-fire over their expenses dating back to May of last year.
Twelve months ago, The Conservative Party Battle Bus rolled up to marginal constituencies around the country in a bid to ensure a Tory victory in the 2015 General Election.
And with some Tory MPs hanging by a thread in parts of Nottinghamshire and Derbyshire, it is perhaps no surprise the bus spent a fair amount of time touring our region.
But here is the problem.
Each MP is allowed to spend a set figure on their local campaigning – and this expenditure must be passed onto the Electoral Commission by individual returning officers at the end of the process for scrutiny.
And none of the Conservative candidates whose constituencies were visited by the bus included the cost within their election budget locally.
About 20 of them could have breached strict campaign spending limits had they declared it – breaching them is a criminal offence and, perhaps more worrying for the current Conservative Government, could lead to by-elections being ordered.
The Tories deny the costs should have been declared as part of local campaigns, instead sticking to a strict line that the bus – or buses to be more precise – were part of national expenditure, and should not be accounted for in individual PM expenses.
Both Nottinghamshire and Derbyshire police forces have now confirmed they have been given another year to investigate the allegations - made against Sherwood MP Mark Spencer, Amber Valley MP Nigel Mills, Erewash MP Maggie Throup and small business minister and Broxtowe MP Anna Soubry.
A Nottinghamshire Police spokesman said: “We are in close contact with the Electoral Commission, the Crown Prosecution Service and other police forces on this matter.
“We are awaiting information from the Electoral Commission. Once we have this we will be able to determine whether an investigation should be conducted.
“Following an application to the court, we have been granted more time to carry out an investigation, if one is required.”
The moves have come following a failed bid by Craig Mackinlay, the Tory MP for South Thanet, to block police attempts to extend the time limit for investigations.
Mr Mackinlay probably has more cause for concern than most - up against UKIP leader Nigel Farage in the Kent constituency, the battle bus was a regular visitor to his constituency.
Derbyshire police also confirmed they have been granted another year to investigate.
A force spokesman said: “We can confirm that the magistrates’ court in Derby granted an extension to the time in which an investigation can be launched into allegations of misuse of election expenses.
“We have not begun an investigation and are awaiting information from the Electoral Commission.”
The problem is simple.
Each battle bus comes with a small army of volunteers – all of whom need feeding, all of whom need a hotel room for the night.
One battle bus stop off in a constituency costs in the region of £2,000.
Those demanding Conservative blood say, in brief, the party has fiddled its expenses by spending more on target constituencies than it is allowed.
The Tories, on the other hand, are saying this was national expenditure which just happened to have been spent locally, but the Party does admit to failing to register the hotel accommodation.
A Conseravative spokesman, on behalf of the four MPs, said: “Conservative campaign headquarters campaigned across the country for the return of a Conservative Government.
“Such campaigning would be part of the national return, not local return, as the Electoral Commission has said.
“As is apparent from our National Return, the Party declared expenditure related to our CCHQ-organised battle bus.
“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 our national battle bus, 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.”
According to reports in the national media, both Mr Spencer and Mrs Throup would still have been below their expenses thresholds, even taking into account the additional costs of the battle bus.
Mr Spencer’s spending limit was £15,187.20 and he declared a total of £12,760. If the additional battle bus expenditure is added, he still has an underspend of £277.20.
Mrs Throup’s spending limit was £15,265.32 and she declared a total of £12,234.25, leading to an underspend of £881.07.
However, both Mr Mills and Ms Soubry would be pushed over the thresholds if the battle bus expenditure was included – Mr Mills by £1,076.53 and Ms Soubry by £1,256.87.
This is politics, obviously, which perhaps explains why there has been such outrage from the Labour ranks.
But if all four MPs faced by-elections as a result, and all four lost, that would leave Prime Minister David Cameron’s parliamentary majority looking decidedly flimsy.
Pictured, from top, Nigel Mills, Mark Spencer, Maggie Throup and Anna Soubry.