MPs representing some of the UK's most Tesco-dominated towns have added their voice to the sustainable high streets campaign, but ministers have missed an opportunity to ensure objective local consultation in planning decisions.

As supermarkets tighten their grip nationwide, campaigners are urging the government to include a statutory duty to promote sustainable high streets in the Localism Bill. A number of MPs have now added their voice to the cause, including Tony Baldry MP, whose North Oxfordshire constituency includes the town of Bicester, which was recently revealed by C-Store as the UK's number one Tesco town.

Baldry wrote to communities minister Bob Neill to seek assurances that the Localism Bill would not undermine the ability of councils to prevent out-of-town supermarket developments. The minister responded that the government was "committed to supporting town centres".

Alan Whitehead, MP for Tesco-heavy Southampton Test, has written several times to the government and secured meetings with local government ministers to "try to ensure that changes to the planning laws mean real power being given to local people on planning issues".

However, neither Baldry nor Whitehead have signed an Early Day Motion (EDM) calling for protection to sustainable high streets, which has been signed by 32 MPs. "I can't see that signing Andrew George's EDM is going to persuade ministers to do something which they are clearly already doing," Baldry said.

In another move, Localism minister Greg Clark refused to support a proposed amendment to the Localism Bill that would require developers to consult communities with objective information.

Introducing the amendment, Jack Dromey MP said: "The duty to consult is an important and positive innovation in planning law." But Clark said the implications of such a move would be damaging. "It would make proper regeneration less likely, rather than more likely," he added.