Unions claim some traffic wardens miss out on perks if they miss targets
Parking enforcement officers face "humiliation" if they fail to meet their targets for issuing parking fines, their unions have claimed.
The unions Unite and Unison say wardens often have to meet targets to qualify for overtime and other perks.
Parking attendants have told the BBC this means some tickets are issued when there is no real justification.
The British Parking Association said ticket-targeting was "unacceptable" and it was trying to stop the practice.
An estimated 10 million parking tickets are issued in the UK every year.
The BBC has been told of the pressures that traffic wardens are under.
Too scared of losing their jobs to speak openly, two different parking attendants spoke anonymously to BBC Breakfast.
One said that every day he was forced to issue tickets that his management knew would be overturned.
"They don't care if they will be appealed, they just want the numbers," he said.
"The bosses tell you to issue tickets even when they know there is a fault in signage.
"Drivers are unjustly battered with tickets and if we don't do it we lose our jobs."
The other attendant told the BBC: "If you hit or exceed the targets you get favours, swapping shifts, and most importantly, if you hit the targets you get overtime.
"People get fired for not reaching their targets."
Unions have backed up up these claims. They have concerns about practices across the UK and particularly where parking enforcement has been contracted out to private companies.
They say staff are often very poorly paid and have to work in a pressured, target-driven environment where they are often bullied and humiliated if they under perform.
Peter Allenson, Unite's National Officer, said: "There are targets that they need to meet and if they don't meet these targets then there are certain things being used against them such as shift swaps and overtime allocation and this is unacceptable."
Parliament's Transport Select Committee has warned councils against using parking tickets to raise revenue.
But Paul Waters of the AA said some local authorities seemed to be doing just that:
"Some councils are blindly issuing tickets, it appears perhaps to get the revenue rather than changing behaviour.
"It is a revenue gainer for many authorities, attendants are exploiting the situation - they know where the honey pots are, and they go along and issue tickets regardless of the fact that the signing is dubious."
But the British Parking Association (BPA) which represents companies who employ parking attendants said it was against ticket-targeting and was making efforts to combat the practice.
A spokesman said: "The BPA considers ticket target-setting totally unacceptable, and as a member organisation we strive to make sure that parking control is about improving the streets, and not making money."