In a letter to Mr Sunak, Jonathan Ashworth, Labour’s shadow paymaster general, said that if the honours were accepted “those who crashed the economy” would be receiving an award for their service.
Former prime minister’s are allowed to put forward names for knighthoods, damehoods, OBEs, CBEs and MBEs, however – given the short period of Ms Truss’s government – concerns have been raised about whether she should have this privilege.
Ms Truss was forced out of office last October after a budget of £45 billion of tax cuts sparked an economic crisis.
Mr Ashworth wrote to the prime minister on Sunday, stating: “Today, families and businesses across Britain are still paying the price for the Conservative Party crashing the economy and leaving working people worse, with higher taxes, higher mortgages and higher food and energy bills.
“Despite this, it has been widely reported that Liz Truss has submitted up to 14 people to receive resignation honours.”
He added: “This means that those who crashed the economy, who left millions to pay more for their mortgage and who undermined our economic institutions could receive an award.
“I urge you to block these honours. You have the power to do so and any response that talks of ‘convention’ is merely a sign of weak leadership and lack of grip over your own party.”
Ms Truss put forward four people for life peerages. According to The Times, two people turned down the offer with one saying they felt it would be “humiliating”.
Former chancellor Kwasi Kwarteng did not make the list, but Ms Truss did include her campaign manager Sir Jon Moynihan and Brexit campaigner Matthew Elliott.
Ms Truss is set to use a speech at the Institute for Government think tank on Monday to defend decisions made during her brief spell in Number 10. She will urge the goverment to cut taxes, shrink welfare spending and raise the retirement age.
She will repeat her attack on the so-called “anti-growth coalition”, and argue that her plan was not implemented due to a reaction from “the political and economic establishment which fed into the markets.”
She will say: “I was effectively forced into a policy reversal under the threat of a UK meltdown.”
But she will concede that she and Mr Kwarteng were in a “rush” to get “results”.
“It is certainly true that I didn’t just try to fatten the pig on market day; I tried to rear the pig and slaughter it as well. I confess to that,” Ms Truss will admit.
Former prime ministers can put forward any number of people of their choosing but the practice was not taken up by Tony Blair or Gordon Brown. It was taken up by David Cameron and followed by Theresa May and Boris Johnson.
By convention, all resignation honours’ requests are granted but it would be within the power of Rishi Sunak to block the proposal of Ms Truss.
Number 10 has been approached for comment.