LABOUR’S left urged leader Sir Keir Starmer to “seize the initiative” and demand proper controls on the soaring price of food today after reports suggested Downing Street is only considering a voluntary scheme for profiteering supermarkets.

A proposed opt-in system, modelled on a similar agreement in France, would allow bosses to choose a limited number of items to cap, according to right-wing newspaper the Sunday Telegraph.

The possible move, which comes as food inflation hits an eye-watering 19.2 per cent, has been compared to pricing controls introduced by then-Tory PM Edward Heath in the 1970s, but Downing Street stressed any initiative would not be compulsory.

“The government is working constructively with supermarkets as to how we address the very real concerns around food inflation and the cost of living, and doing so in a way that is also very mindful to the impact on suppliers,” Health Secretary Steve Barclay told the BBC’s Sunday with Laura Kuenssberg programme.

The North East Cambridgeshire MP claimed that fears smaller business would be under “significant pressure” meant the proposals, which a No 10 source said are still at the “drawing board stage,” are “not about any element of compulsion.”

The British Retail Consortium blamed the sharpest rise in food inflation for nearly half a century on the “soaring cost of energy, transport and labour, as well as higher prices paid to food manufacturers and farmers.”

However, according to analysis from Unite the union, Tory ministers have allowed major supermarkets to get away with corporate profiteering while using their enormous purchasing power to negotiate beneficial deals with under-pressure suppliers.

Shadow work and pensions secretary Jonathan Ashworth appeared to dismiss any form of price cap earlier today, telling Sky News that Prime Minister Rishi Sunak is “now like a sort of latter-day Edward Heath with price controls.”

But ex-shadow chancellor John McDonnell demanded proper action and warned that a “voluntary agreement limited to only a few foods will just be an ineffective publicity stunt.”

He tweeted: “[I’ve] been calling for price controls on basic food stuffs & rents for 18 months — Labour has an opportunity now to seize the initiative on controlling prices & rents.”

His Socialist Campaign Group of Labour MPs colleague Richard Burgon echoed the calls, telling Twitter: “I first called for this over a year ago and did so again in Parliament earlier this month.

“The government must do this. And without any further delay.”

The demand came just days after the Leeds East MP told the Morning Star that the government must tackle “greedflation” across the economy by introducing price caps on staple foods and rents and taking “rip-off” water and energy companies into public ownership.

Any attempt by Mr Sunak to introduce even a limited voluntary scheme is likely to worsen a growing rebellion by Tory free-marketeers following the party’s loss of more than 1,000 councillors in English local elections earlier this month.

Nile Gardiner, a former aide to neoliberal heroine Margaret Thatcher, tweeted today: “No Conservative [government] should be implementing price caps.

“This is fundamentally against the free market and is an attack on economic freedom.”