Prime minister Gordon Brown has proposed looser data protection laws, which could lead to tax information being handed to private firms.
Three bills in the prime minister's draft legislative programme propose increased data sharing power, and one measure would hand HM Revenue and Customs (HMRC) data to private firms.
Brown's predecessor, Tony Blair, had also proposed a relaxation of the data protection laws to allow greater data sharing between government agencies – a move he said would improve public services by reducing the amount of form-filling for individuals.
But Brown's measures are included in planned legislation that is not focused on welfare or improving public services.
Instead, the draft legislative program – a departure from the tradition of announcing government bills in the queen's speech – includes increased data sharing powers in proposed new laws on terrorism, education and skills and the sale of student loans.
A proposed Counter Terrorism Bill would help the investigation of terrorism by giving data sharing powers to the police, intelligence and security agencies, and would also put the police counter-terrorist DNA database "on a sound statutory footing," the draft program says.
An Education and Skills Bill outlined in the program would include measures described as "subject to policy clearance" that would enable data sharing, particularly with HM Revenue and Customs and the Department for Work and Pensions.
The proposed bill's main measures would raise the school leaving age and ensure training for adults in employment, but the program says the data sharing powers would "help report on whether the system as a whole is delivering economically valuable skills" – a statement that may suggest the government will seek to check individuals' employment status or income after training.
Brown is also proposing to sell off the student loans portfolio, which is due to generate £6 billion receipts over the next three years. Data sharing powers included in a Sale of Student Loans Bill would allow information on the loans held by HM Revenue and Customs to be disclosed to the purchasing company.
The proposals are likely to stoke anger from privacy campaigners and opposition parties, who had already voiced concerns about Blair's proposals.
Information commissioner Richard Thomas has so far stopped short of opposing government proposals to amend the data protection laws to allow greater data sharing. But in May he told public bodies they must carry out an analysis of risks and benefits to individuals and society before sharing personal data between agencies.
Ministers announced the extension of a pilot project sharing data between the Department of Work and Pensions, HM Revenue and Customs and local authorities last month, although the six local authorities thought to be involved had not confirmed participation in the scheme.
Under former home secretary John Reid, the Home Office also issued a call for sharply increased data sharing powers in an immigration rules enforcement strategy published in March.