T esco's planning tactics have come under fresh scrutiny recently, thanks to a seemingly inno­cuous decision to build a small extension to the back of its Bury St Edmunds store.

Unfortunately, the development didn't comply with the original planning permission. Local planning authorities are now accusing the retailer of playing fast and loose with the planning regime by making changes to stores without permission and then seeking consent retrospectively. But are they over-reacting to what many argue is a perfectly legitimate tactic - and one that Tesco is not alone in using?

It's not the first time Tesco has been criticised for its use of retrospective planning applications. Three years ago it developed a store in Stockport, Greater Manchester, 20% bigger than its planning consent allowed. It eventually won the battle for retrospective consent and apologised for its oversight, but not without incurring the wrath of anti-supermarket campaigners.

It has since submitted a number of other retrospective applications including Bury St Edmunds, where the row centres on its use of white sheet cladding material and the height of the extension, which is being used for storage and online deliveries. St Edmundsbury Council is currently discussing potential modifications with the retailer with a view to a retrospective application, but Tesco's decision to build without consent has put noses out of joint. "They have used a cladding which is very noticeable," says Patsy Bell, head of planning and environmental services at St Edmundsbury Council. "The problem is its height and its effect on neighbouring houses."

It's a similar story in Southampton, where councillors recently gave Tesco retrospective planning permission for previously unauthorised changes to access arrangements and the roofs, signs, drains and rear door of an Express in Bitterne Park.

"Tesco gave the impression it was quite cavalier about how it was built and that it would do it its way regardless of the planning consent," says councillor June Bridle, chairman of Southampton's planning committee. "We had to approve something that had already been done."

However, Tesco is far from the only retailer to face criticism over its planning tactics. Aldi had to apply for retrospective planning permission for signage in Chorley, Lancashire, in March and Morrisons also sought retrospective planning ­permission for trolley shelters at its Belper store in Derbyshire.

In fact, it is reasonably commonplace for supermarkets to start building without planning permission, according to Malcolm Honour, head of retail at planning consultancy CgMs.

He argues that the decision to build usually happens when a council has agreed in principle to a scheme, but has not finalised the details. "It is a risk from the retailer's point of view, but issues such as the landscaping scheme are usually approved along the way," he says. "You can wait months for a council to come back to you, but the supermarket will still be subject to commercial pressures."

Honour adds that most retrospective applications typically revolve around minor issues, such as delivery hours or access, and many are the result of innocent mistakes. Most retrospective planning applications from retailers concern nothing more serious than trolley shelters.

The question is whether this is always true in Tesco's case. At its store in Gunness, Lincolnshire, for instance, the original planning consent restricted the amount of space that could be devoted to non food to 25%. But, according to North Lincolnshire's head of planning, Mike Welton, within 18 months of the store opening in 2001 it became apparent that the floorspace had been increased beyond that limit.

Tesco submitted a retrospective application, which was refused. However, following an appeal by Tesco, the inspector came down in the retailer's favour.

"It seems that Tesco was blatantly ignoring the restrictions of the planning permission," says Welton. "We tried to put across the view that Tesco effectively had no intention of trading within the 25% level, but it was difficult to prove."

Tesco insists that most of its retrospective applications are over fairly trivial matters and, as in the Bury St Edmunds case, not floorspace. "It is all down to interpretation of the architects' plans, but we have a good relationship with the council and will re-submit an application in line with the council's wishes," says corporate affairs manager Michael Kissman of the Bury St Edmunds situation. "We don't want to end up going down the enforcement or appeal route."

The problem lies with the planning system, which for years has been under-resourced and over-stretched, he suggests.

"The planning system can be slow and it can take a few years to get consent for a new store," he says. "By that time, we may be able to improve on the design and we would want to amend a scheme to reflect the latest thinking to provide the best possible store, rather than an out-of-date plan.

"We would always do this in consultation with local planners, even if we did not have the formal consent, but we would welcome any changes to the planning system that could speed things up."

Needless to say, the likes of Friends of the Earth do not see the methods of the supermarkets in quite such a benign light. "Tactics such as retrospective planning consent are ways in which the big supermarkets abuse their power within the planning system," says supermarkets campaigner Sandra Bell.

"Local authorities are very mismatched in terms of resources to resist some of the underhand techniques. It is certainly harder for councils to refuse a built store than an application for that sort of store at the outset. It is taking away the whole democratic nature of the planning system."

Bell dismisses claims that retrospective applications are the result of honest mistakes. "It is hard to see how building a store 20% larger is an oversight," she adds. "A lot of the practices are not necessarily illegal but do show disrespect for the planning process. Tesco, in particular, is continually trying to argue its way out of conditions that local authorities have put in place to protect the character of town centres."

The Association of Convenience Stores agrees. "Retailers have a number of different means of getting their way in the planning system," says spokesman Shane Brennan. "Retrospective applications are the sort of tactic that's only available to those with substantial financial means and resources."

Maybe not for much longer. Councils are becoming more rigid in their interpretation of planning guidance and are more inclined to take action than in the past, says Honour. With campaigners and the general public on their backs, retailers will have to ask themselves whether retrospective applications are worth it, given the negative PR.n