The public health minister Melanie Johnson warned fast food companies to end two-for-one burger promotions and incentives aimed at children.

She accused them of sending "contradictory messages" in the battle against rising obesity levels. The government has already put the food industry on notice that manufacturers will be banned from advertising products that are high in fat, sugar and salt unless they put their own house in order.

Johnson has successfully forced some companies to drastically reduce salt in foods but her remarks over two-for-one promotions, such as those offered by McDonald's and competitors, and toy offers with meals for children represent a significant ratcheting up of rhetoric.