JEREMY Corbyn is at the centre of a racism row after a shadow Labour minister criticised the party leader’s behaviour towards two ethnic minority female MPs.

Chi Onwurah, the shadow minister for culture and the digital economy, claimed Mr Corbyn had "picked on" her and her colleague Thangam Debbonaire and had made it "impossible" for them to do their jobs properly.

The Newcastle MP suggested her leader’s behaviour could have led to a racial discrimination case if he had been a private sector boss.

The allegation – denied by Mr Corbyn’s office - came as Kezia Dugdale threw her weight behind leadership challenger Owen Smith, saying he was best placed to unite the party and provide a credible plan for government. The Scottish Labour leader also argued that Mr Corbyn should take some responsibility for the party’s decline in Scotland.

READ MORE: Jeremy Corbyn must accept some responsibility for Labour's decline in Scotland, Kezia Dugdale suggests

After the controversy over anti-Semitism within Labour, the party leader – due to face Mr Smith in the Scottish hustings in Glasgow on Thursday – is now embroiled in another discrimination row.

Ms Onwurah said her leader had "undermined" both women when he gave part of her shadow cabinet brief to Ms Debbonaire without telling her.

The shadow minister said Mr Corbyn then returned the role to her without informing Ms Debbonaire.

Writing in the left-wing New Statesman magazine, Ms Onwurah said: "If this had been any of my previous employers in the public and private sectors Jeremy might well have found himself before an industrial tribunal for constructive dismissal, probably with racial discrimination thrown in; given that only five per cent of MPs are black and female, picking on us two is statistically interesting to say the least.

READ MORE: Jeremy Corbyn must accept some responsibility for Labour's decline in Scotland, Kezia Dugdale suggests

"Indeed as Thangam was undergoing treatment for cancer at the time he could have faced disability action as well,” said Ms Onwurah.

She added: "In any other job I would have called on my union for support in confronting an all-white management which prevented two of its few black employees from doing their jobs. I would have expected the leader of the Labour Party to condemn such ineffectual management which allowed such abuse."

But a spokesman from Mr Corbyn explained how the issue raised by Ms Onwurah referred to the delineation of shadow cabinet roles.

"When Thangam Debbonaire was appointed as a dedicated shadow minister for the arts in January there was a negotiation about the division of responsibilities with Chi and Thangam but at no point was anyone sacked. We regret Chi feels she was singled out but this was clearly not the case,” he added.

READ MORE: Jeremy Corbyn must accept some responsibility for Labour's decline in Scotland, Kezia Dugdale suggests

Previously, Ms Debbonaire, who represents Bristol West, had claimed that she was hired and fired from the Labour front bench without ever being informed; an incident the Labour leader reportedly put down to a "miscommunication".

As the ballots went out to the 640,000 eligible voters, Ms Dugdale decried Labour in-fighting, which she said had created an "almighty, ugly mess" for the party.

The Scottish Labour leader said she knew what skills and discipline were needed to run a campaign, which was why she was backing Mr Smith.

“I know what happens when a party repeatedly refuses to listen to the message that the electorate is saying; when repeatedly it seems out of touch. That is the consequence of what has happened in Scotland, which has led Labour to come third in most recent Scottish parliamentary elections."

The Lothian MSP upbraided the UK party leader, noting: "He was claiming success for Sadiq Khan's victory in the[London] mayoral election; he can't claim the credit for that and not accept any responsibility for what's happening in Scotland."

In May, Scottish Labour lost 13 seats and came third behind Ruth Davidson's Scottish Conservatives.

READ MORE: Jeremy Corbyn must accept some responsibility for Labour's decline in Scotland, Kezia Dugdale suggests

On the campaign trail, Mr Smith promised to hand over more power to party members and give them the final sign-off on manifesto pledges.

His intervention came after Mr Corbyn had earlier pledged to strengthen trade union bargaining powers if he became prime minister.

The leader’s promise was made as Unite, Scotland’s biggest trade union, re-affirmed its endorsement of his leadership.