His complaints against fellow councillors could cost £120,000 to investigate – putting vital cash-strapped public services under threat – but now a court fine for putting up posters for a charity open day has made Chris Byrne put his costly pen to paper yet again.

Councillor Byrne has long operated charity fundraisers at the former home of comedian Frankie Howerd in Somerset, where he lives, raising thousands for good causes. But when Sedgemoor District Council discovered he had put up advertising signs for a recent event without permission, he was fined £800, and ordered to pay nearly £200 in costs.

The much-publicised councillor has earned a notorious reputation for complaining about other councillors – and a string of complaints to the Standards Board for England means Sedgemoor is obliged to shell out tens of thousands to investigate

Mr Byrne believes that district councillor John Denbee alerted the council to the posters and he is angry that he appears to have been singled out for chastisement when other people who have put up signs advertising other ventures have not been prosecuted.

So he has filed another complaint about Mr Denbee, likely to cost the taxpayer another few hundred pounds to investigate. So far, none of his complaints have been upheld.

Mr Byrne lives at Howerd's former home, Wavering Down and has raised thousands for the Frankie Howerd OBE Trust and other good causes by holding open days for several years.

The Western Daily Press spoke to Mr Denbee and he denies he reported Mr Byrne. The two have crossed swords on other issues in the past and a previous complaint brought against him by Mr Byrne has been rejected by Sedgemoor's standards committee in recent weeks.

Mr Byrne said: "I realise I was in the wrong to put up the signs but, at the time, I noticed at least 29 other displays in the area, some of which were much larger than mine. I believe Cllr Denbee used his position to encourage the enforcement officer to view my signs.

"Other people who have put up signs in the area have not been told to remove them. I have made an official complaint to the monitoring officer saying this is being done out of personal animosity."

Mr Byrne has now made more than 100 complaints to the Standards Committee, involving parish councillors of various councils on which he serves, and against Mr Denbee. Sedgemoor District Council has said that investigations for the first half of the year have cost £52,800, expects the second half to cost the same and warned that it may need a supplementary estimate of £20,000 for other costs and a further £35,000 to carry out its duties next year. Sedgemoor's chief executive, Kerry Rickards, is to meet Cllr Byrne next month to discuss the situation.

Cllr Byrne says it is the price of democracy and that he has spent £30,000 of his own money on legal fees for standards committee hearings.