Opposition is rising to a policy that would make calorie counting mandatory in restaurants, with the Treasury saying it is likely to block the move to protect small businesses.
The policy, which is being pushed by the health department's new minister Matt Hancock, would see all food outlets forced to declare the calorie counts of their dishes.
However, sources in the Treasury have hit out at the move, which is currently under consultation. The policy will be unable to move forward without the department's approval.
In a leaked letter, the chief secretary to the Treasury, Liz Truss (pictured), told the prime minister's right-hand man, David Lidington, that her department would be likely to block the policy as it stands.
She wrote: "I am concerned these proposals could result in job losses and higher food prices being passed on to consumers.
"It could cost businesses, including SMEs, up to £13m (an average of £500 each for 26,000 businesses per year), and individual costs may be particularly burdensome to micro and small businesses, which frequently change their menus to offer seasonal local foods.
"I am also concerned that the accompanying impact assessment may underestimate the cost to businesses of ongoing compliance with complex and specific new regulations."
She added that "at this stage I am not agreeing to any preferred option or final policy change for small or micro businesses.