Runners in Sunday's Race for Life in St Albans have been left outraged after receiving car parking tickets while taking part in the charity event.
Participants and supporters who had parked on grass verges on Bluehouse Hill returned to their cars to discover they had been fined.
Traffic wardens gave out a total of 42 parking tickets while runners were taking part in the 5k and 10k race around Verulamium Park.
Ursula Parsons, who went along to support her daughter in the race, said she was "disgusted" to receive a ticket.
The 54-year-old said: "This as a well coordinated attack. There was hardly any parking around and when we saw around 20 to 30 cars on the grass verge we decided to park there.
"Then when everyone was either watching or taking part in the race the wardens went on the attack."
Ms Parsons said she felt the tickets were shameful and a "planned attack".
She continued: "We were warned on the tannoy but were too late to avoid a ticket. There were around eight traffic wardens who appeared out of nowhere. It was obviously planned, I don’t care what the council say. I have never seen a traffic warden on a Sunday in all my 20 years here.
"The council should be ashamed of themselves. They are money grabbers and they planned to make a killing. We were not blocking anyone and it was not dangerous.
"We were fuming, and to top it off I missed my daughter crossing the finish line. I suggest the council donate the money to charity."
St Albans District Council had worked with Race for Life organisers to warn people about illegally parking days before the event was due to take place.
Julie Braithwaite, event manager for the St Albans fundraiser, said: "It is obviously very unfortunate that people were ticketed and I can sympathise, but these people were parking on double yellow lines.
"This is beginning to happen every year. The race is in the city centre and is very accessible.
"I think the problem is that people leave it until last minute to get to the site and then they worry they will not make it and park illegally.
"Parking in St Albans on a Sunday is only £1. We worked with parking services this year and I think we did all we could to warn people.
"The race itself was fantastic and although it was very hot we have had great feedback."
Signs to warn drivers they would be fined if they parked on the verges of Bluehouse Hill were put up by the council.
Charles Turner from St Albans City and District Council’s legal, democratic and regulatory services department, said: "Parking restrictions at Bluehouse Hill were put in place in 2012 for safety reasons, as it is a busy road with fast-moving traffic, and also to prevent damage to grass verges. There is clear signage advising drivers that parking on the verges is not allowed at any time.
"Bluehouse Hill can become busy during the summer months due to the popularity of Verulamium Park and it is checked regularly for illegally parked vehicles. We did not increase the level of deployment of parking officers operating in the City for the event.
"We are sorry that given the nature of Race for Life, some of the people who received a penalty charge notice had come to watch or take part in the event, however, we have to treat everyone equally.
"If anyone has received a penalty notice and believe they should not have to pay it, they should contact the council. We will consider all cases on their individual circumstances.
"We will be liaising with race organisers in the future to see if anything more can be done to help direct spectators and participants to near-by car parks. As a gesture of goodwill we will be making a donation to Cancer Research UK’s Race for Life."
The fine is £70, which is reduced to £35 when it is paid within two weeks.