Bristol Rovers fans say they are frustrated by the lack of progress on the club's plans to redevelop the Memorial Stadium.

Planning permission to transform the Mem into a 18,500-seater stadium as part of a £35 million project was agreed almost three years ago.

But work is yet to start and Rovers' chairman Nick Higgs yesterday admitted progress was still "painfully slow", although he insisted work to secure funding for the stadium in Horfield was continuing behind the scenes.

Supporters are being asked to remain patient but some Gasheads say it is difficult to accept the lack of progress when an air of excitement surrounds Bristol City's plans for a new stadium at Ashton Vale and the associated 2018 World Cup bid.

Gary Marks, chairman of Gas Independent Fans' Trust (Gift), said he was worried the gulf between City and Rovers could grow if a new stadium is built at Ashton Vale and the Memorial Stadium remains undeveloped. He said football in Bristol could mirror that of Stoke-on-Trent, where Port Vale struggles while Stoke City has received investment for a new stadium and established itself in the Premier League.

Mr Marks said: "My worry is that we will increasingly become the poor relations of Bristol City. Rovers need to put an end to the rumour mill because there have been a lot of Chinese whispers among supporters.

"The club has nothing to fear by being more open with everyone about what is happening – we all want this to succeed and are desperate for it to go ahead.

"People are looking across the river and that's accelerating the sense of urgency amongst fans. We don't want to be the Port Vale to Bristol City's Stoke."

Jim Chappell, chairman of Bristol Rovers Supporters' Club, said he too was frustrated.

He said: "Everyone is frustrated by the amount of work they are having to do behind the scenes.

"But from the position we were in 10 years ago, we own our own ground and are positive the new stadium will be developed. We have to believe what the directors are saying.

"With City getting planning permission for their new stadium it does make it worse."

In October 2008, Rovers announced they were planning to stay at the Memorial Stadium during the redevelopment instead of moving to Cheltenham Town's ground for home matches.

Planning permission was granted for the new ground in January 2007 and the plans have since been revised.

The club hope the stadium will be built complete with a hotel and student accommodation, which will help fund the project.

Developer Opal Property Group pulled out of a deal to build and manage the student accommodation attached to the stadium in summer 2008.

The club had hoped to start work this summer and it was expected the redevelopment would take two years and be complete by the start of the 2011-12 season.

The club has refused to confirm whether it is still aiming to play matches at the new stadium for the beginning of the 2011-12 season.

Mr Higgs said: "There has been a lot of talk recently about the lack of any fresh information regarding the stadium regeneration project.

"While I understand your frustration – no one is more frustrated than me – we are subject to a number of confidentiality agreements with our various partners, and do not want to jeopardise proceedings by releasing information at the wrong time.

"I do not want to be forced into saying something that I later regret, but I can assure you that there is still a lot of work going on behind the scenes and things are moving in the right direction, but we realise that progress is painfully slow."