Eric Pickles, the Local Government Secretary, is planning to allow motorists to park on double yellow lines outside shops or keep their vehicles in parking bays for longer in an attempt to stimulate businesses on the nation’s high streets.

However, the Conservatives are likely to meet opposition from their Liberal Democrat partners in government, who have flagged up concerns that a grace period will prove unworkable. The Liberal Democrats also want to raise the cap on all illegal parking fines, not just those for dangerous parking. At present, the cap on fines outside London is £70 compared with £130 within the capital.

Mr Pickles first suggested a grace period in May of this year, when he said that local authorities were using motorists as ‘cash cows’ with parking fines. A source close to Mr Pickles said: “The high street is in danger of dying off, and over aggressive parking enforcement is part of the reason. If people are worried about paying a fortune in fines, it will make them more likely to shop online or go to out of town shopping centres. For too long, parking has been a revenue raiser. Its time to end that.”

Many local authorities already allow motorists to park for free for 30 mins close to shops. The Conservatives want to implement similar schemes across Britain. This could be introduced by either amending existing legislation or creating new guidance for local authorities.

Norman Baker, the Liberal Democrat transport minister, said: We are keen to ensure that the high street works for businesses by stopping people parking illegally for hours on end. This is about tackling motorists who are parking illegally, not about raising charges for those who park legally”

Mr Pickles and other Conservative ministers are opposed to Liberal Democrat plans to lift the cap on parking fines outside of the capital. He said: “Lifting the cap on parking fines across the board would make parking fines bigger than the penalties given to shoplifters. It would be criminalising people who want to go shopping.”