In general elections the amount that a candidate and their party can spend in the campaign is limited by law. For a normal General election there are limits for the early part of the campaign, called the long period which are very high. There is then a much lower limit for the last 6 weeks which is called the short period.
For Nuneaton in 2015 the short period limit seems to have been £14,768. Marcus Jones and his agent claimed to have spent £13,435 during this short period. However a channel 4 investigation found out that a battle bus full of activist was used in the last week of the election to get his vote out. The considerable costs including hotel costs should have been recoded against each candidates local spending as they where doing local campaigning in the name of the candidate.
See channel 4 investigation website
I did my own investigation and found a string of issues with the spending recorded against the short period. The best example are the at last 7 videos Marcus had produced for use in the last weeks of his campaign. These should clearly be booked in full to the short account but only £597 was booked to that from an invoice for the first instalment. It is also unclear what the final bill was.
There are was also significant anomalies with the claimed cost of leaflets. The expenses ignore part of the costs of many leaflets as it was claimed they where not all used. This is a great way to claim the campaign cost less but printing 2000 costs more than 1/5th the cost of printing 10,000 with normal commercial printers.
I will post up more later and welcome more information.