Top judges will decide whether Barnet Council was lawful in more than doubling the cost of parking in the borough’s controlled residential zones.

Campaign group Barnet CPZ Action claims the charges, introduced early in 2011, are unlawful and members launched a legal bid last year.

The challenge appeared to have stalled when it was dismissed at the Royal Courts of Justice in February but yesterday a judge at the Court of Appeal ruled the case must go to a full hearing.

Founding member of the group David Attfield is elated by the decision which he has fought for nearly a year to secure.

He said: “It is a huge step forward for the group and I’m delighted. We will finally have our day in court where the lawfulness of these charges will be tested.”

The group argues the council should not be allowed to increase costs for people living in CPZs, which makes up just ten per cent of the borough, to subsidise other transport provision for the whole of Barnet.

Barnet Council hoped to raise in the region of £1.6 million through the additional charges to spend on wider transport services, a move the group argues is unlawful.

A top legal team agreed to take on the case on a no-win no-fee basis and yesterday’s decision means the council faces a huge legal bill and an embarrassing u-turn if the challenge is upheld.

A statement released by the authority said it was aware the appeal had been granted but was unable to comment further as it is awaiting legal papers from the court.

No date has yet been set for the hearing but father-of-two Mr Attfield hopes it will be concluded by the end of the summer.

Mr Attfield, of Summerlee Avenue, said: “I wasn’t completely surprised at the decision as I have always believed in the strength of our case but now the legal fight has sprung back to life and is bang on track. This will be a full examination of the law and the facts.”

People living within CPZ areas have seen charges increase substantially in the past 13 months.

The cost of a visitor permit has risen from £1 to £4.17 per day while residential permits have increased from £42 to £105.

Mr Attfield says he feels no guilt about the prospect of the taxpayer footing the council’s legal bill should his group be successful, claiming the authority should have listened to residents earlier.

He said: “They will only have to pay out if it is found they acted unlawfully so from that perspective my conscience is clean. We begged and pleaded with them to find a more appropriate way of charging but they did not listen.

“The charges have become a prohibitive cost which can leave you spending £50 on parking just to hold a children’s birthday party. We have a full trial to await and we’re taking nothing for granted but we are pleased with the decision.”