SNP ministers have been criticised for failing to go far enough in extending the scope of freedom of information laws.

Tavish Scott, the Liberal Democrat MSP, said the Scottish Government had been "working in the shadows" having signed "secretive" multi-million pound deals with private firms not subject to FoI despite having responsibility for building schools, hospitals and major infrastructure projects.

A report by the Information Commissioner has criticised a lack of progress in extending coverage of the laws, which give the public the right to information held by most public bodies. Concern has been expressed that the outsourcing and privatisation of more services, to bodies not under FoI, has eroded rights.

The Scottish Government extended coverage to arms-length council organisations that provide leisure, cultural and sporting services last year. However, it is yet to extend the laws to housing associations, although ministers have said they will consult on the issue after initially appearing to rule the move out.

Mr Scott, a former leader of the Scottish LibDems, called on ministers to go further. He said: "They like to boast about the number of schools being built across the country and how it’s promoting the multi-million-pound construction industry but it seems they prefer to keep the details of their deals secret.

"The SNP has been in power for eight years now and since being in government they have extended FOI just once. But the public don’t just want to know about the workings of culture and leisure trusts, they want to know about the contractors maintaining our roads, the construction firms building our schools and the housing associations providing shelter... SNP ministers want to keep working in the shadows."

A government spokesman Scotland’s freedom of information legislation is the most robust and up-to-date in the UK. He added: "This government has already extended the system to make it even more open by covering a range of local authority arm’s length bodies responsible for leisure, cultural and sporting facilities, as well as the new health and social care joint boards."