The boss of the chocolate maker – also chairman at Centrica – is urging ministers to look at measures that could protect potential strategic assets from takeovers by overseas groups.
His calls follow last week's victory by US firm Kraft Foods in its takeover battle for Cadbury after the Dairy Milk maker's board backed an 850p-a-share offer, which looks likely end a 186-year independent history.
Carr told a Sunday newspaper the government could have intervened in the Cadbury deal and "stopped it all overnight".
"But not one action was ever taken," he said, adding: "If the government is concerned about these events, it has to look at ways of preventing them.
"I'm against protectionism or meddling with voting rights, but it is up to the government to decide whether something is a strategic asset."
The government must decide if Centrica is a strategic asset now to head off any possible unwanted overseas takeover attention, he warned. Centrica is widely rumoured to be a takeover target for the Russian energy group Gazprom.
Carr said: "If they (the government] don't decide that this is a strategic asset then there is always the possibility of the company being vulnerable – they have to think about it now rather than when it happens."
At present, only three major British companies are protected from takeover – Royal Mail, BAE Systems and Rolls-Royce.