BORIS Johnson is facing yet another backlash from his own party over plans to slash the international aid budget as part of a sweeping Spending Review.

The announcement was met with widespread condemnation by opposition MPs, as well as health experts.

But now several prominent Conservatives have publicly expressed concern at the move – which breaks a manifesto pledge – as the Government's economic forecasts were questioned by some economists.

The overseas aid cut was announced by Chancellor Rishi Sunak as one of a number of measures intended to help cope with the economy contracting by an expected 11.3% this year.

READ MORE: Rishi Sunak slammed for ‘deplorable’ cut to aid that may cause ‘100,000 deaths’

The Prime Minister and Sunak addressed a virtual meeting of the 1922 Committee of Tory backbench MPs on Wednesday night to try and firm up support for their approach.

Former foreign secretary Jeremy Hunt and ex-prime minister David Cameron, were among those criticising the plans to cut overseas aid from 0.7% to 0.5% of gross national income (GNI).

The GNI in 2019 was £2.17 trillion, meaning a drop from 0.7% to 0.5% would account for more than £4bn.

It prompted Foreign Office minister Liz Sugg to quit in protest and, in her resignation letter to Johnson, she called it the "fundamentally wrong" move, telling the Prime Minister it would "diminish our power to influence other nations to do what is right".

Other Tories critical of the move included former international development secretary Andrew Mitchell and chairman of the Commons defence committee Tobias Ellwood.

The National: Tobias Ellwood is among the rebelling Tory MPsTobias Ellwood is among the rebelling Tory MPs

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Archbishop of Canterbury Justin Welby said it was "shameful and wrong" while Mitchell said it would be "the cause of 100,000 preventable deaths, mainly among children".

Ellwood warned China and Russia are likely to extend their "authoritarian influence" as a result of the "vacuum" created by the UK "downgrading" its soft power programmes.

Sunak said the 0.5% equated to around £10bn in aid and defended the cut, adding: "Sticking rigidly to spending 0.7% of our national income on overseas aid is difficult to justify to the British people, especially when we're seeing the highest peacetime levels of borrowing on record."

The Chancellor earlier said the economy was not scheduled to recover to pre-crisis levels until the end of 2022.

Emergency measures will see the Government borrow £394 billion this year, which amounts to 19% of Gross Domestic Product (GDP), a measure of the size of the economy – the highest ever recorded in peacetime.

However, head of the Institute for Fiscal Policy (IFS) Paul Johnson questioned whether more borrowing than that signalled by the Government would be needed.

He Tweeted: "SR (Spending Review) assumes zero spending on Covid after next year. It assumes Universal Credit is cut in April. It assumes non-Covid spending will be £10bn p.a. less than expected in March. Not sure any of these will happen. Implying quite a lot more borrowing even than the £100bn forecast."