The launch of the government's Responsibility Deal has slipped back after it scrambled to fine-tune details of industry pledges.

The government is working with industry, the voluntary sector, NGOs and local government to agree on voluntary actions they can take to help people make healthier choices.

Pledges were widely expected to be unveiled on 28 February but the launch date has been deferred until mid-March at the earliest, according to sources in the government's Food Network.

Secretary of state for health Andrew Lansley has now formally invited companies to sign up to three specific food pledges linked to reductions in salt, transfats and calorie labelling of menus by 7 March.

However, he stressed, that there would still be ­opportunities for those who could not meet the deadline to sign up at a later stage. A launch date for the deal had not yet been decided, said a Department of Health spokeswoman this week.

Once responses were in, the network would look to secure a slot in the government's communications cycle.

Certain pledges were proving more challenging than others, but procedural complications rather than lack of agreement were the main reason for delay, industry sources insisted.

Federation of Bakers director Gordon Polson said the process had been very fluid and "things had changed at the last minute".