Dominic Raab has said he will not publish legal advice related to the decision to cut the foreign aid budget following claims that the Government is acting unlawfully.

The Foreign Secretary insisted that the Government was acting in line with the 2015 law that sets the aid target, amid calls from MPs for a Commons vote on the controversial measures.

Foreign Office minister Baroness Sugg quit in protest at the plan to slash the budget to 0.5% of gross national income (GNI) from 0.7%, in spite of promises not to reduce it in the Tory manifesto.

During a session of the Lords International Relations and Defence Committee, Baroness Sugg asked Mr Raab if there were plans to introduce legislation to ensure the Government is acting in accordance with its statutory obligations.

The Foreign Secretary told the committee on Tuesday: “As you know, the position that we set out is that we intend to return to 0.7% when the fiscal situation allows.

“We are acting in line with the International Development Act 2015, and that of course explicitly envisages circumstances where the 0.7% target is not met.

“Of course there is a limit to that scope as well, so I’m looking very carefully at the issue and will inform the House precisely how we intend to proceed in due course.”

However, a legal opinion by the former director of public prosecutions, Lord Macdonald of River Glaven, warned last month that plans to abandon the commitment without passing new legislation would be unlawful.

The opinion, commissioned by senior Tories opposed to the decision to reduce aid spending, said the Foreign Secretary had no power to change the target, which was enshrined in law by a 2015 act of Parliament.

Baroness Sugg also asked Mr Raab if he agreed that if the 0.7% commitment is not met for more than one year, then primary legislation would be “definitely needed”.

She added: “Would it be possible to share the legal advice that you based your original statement on and any change to that advice that you have received since?”

In response, the Foreign Secretary told MPs: “I don’t think, in answer to the first, it’s quite as straightjacketed as that.

“It’s fair to say that there’s limits, and temporal limits, set out in the Act.

“And as you well know, as a former minister of some renown, that the Government doesn’t share regularly its legal advice.

“We don’t regularly publish legal advice and certainly not all of the different conversations we have, and there’s good reason for that – we want to be able to have thorough and frank discussions.”

In November, the Government announced the plan to temporarily slash the aid budget to help repair damage to public finances caused by the coronavirus pandemic.

The Foreign Secretary last week set out the priorities for how the £8.11 billion of the aid budget will be allocated by the Foreign Office – approximately 80% of the total UK spend.

He faced accusations of “sneaking out” the cuts to the budget – branded “draconian” by Tory former international development secretary Andrew Mitchell.

Some 200 UK charities said in a joint statement that cuts to the foreign aid budget represented a “tragic blow” for many of the world’s most at-risk communities.