The imbalance of power between local authorities and community groups could undermine the provision of the Localism Bill that aims to devolve power, according to the crossbench peer Lord Mawson.
The bill, which had its second reading in the House of Lords on Tuesday, creates new rights for local people and community groups.
They include a ‘right to challenge’, under which councils would be obliged to consider proposals by community groups to improve local services, and a ‘right to bid’ to buy community assets, such as shops, pubs and post offices.
During a seven-hour debate, Mawson said the bill contained important opportunities for local communities, but the disproportionate relationship between councils and community groups might "result in the local authority holding all the cards".
Councils, he said, would use their "full hand to prevent change, despite any paper reassurances that the bill can offer to the contrary".
He asked: "Will this bill actually be practicable for a local social enterprise to successfully challenge its local authority and seek to run a service?
"The key, I believe, lies with who decides the specifications of the service and the cost. Will that person be independent and local so that the devil in the detail is understood?"
The Labour peers Lord Boateng and Baroness Warwick of Undercliffe both said that public sector funding cuts were undermining the chance that charities would benefit from the bill.
"Far from doing more, as the government asserts, they may be able to do rather less," said Warwick. "Vital services cannot simply be shifted to voluntary groups as a way of cutting spending."
Lord Wei, an adviser to the Community Foundation Network and the government’s former big society adviser, described the bill as "an incredibly significant piece of legislation in that it sets out some of the key foundations for the big society, enabling a major shift by decentralising power and strengthening local initiative".