‘GET your house in order” – the SNP’s Westminster economy spokesperson says HMRC must take urgent action over a catalogue of bungles and blunders involving Scottish firms.

In one incident, a construction industry sub-contractor left out-of-work since March was told it will take until Christmas Eve to begin processing the tax rebate claim he’s relying on to pay his rent.

In another, a business waited months for a furlough payment only to have HMRC take the five-figure payment back from its bank account the following day.

Queues on HMRC helplines are said to be so long that it can take 90 minutes to speak to an operator.

HMRC says it “doesn’t recognise” the testimonies given to the Sunday National by stressed traders who say dealing with Her Majesty’s Revenue and Customs is making it harder to survive the pandemic.

But Alison Thewliss MP, who leads on the economy for the SNP in the House of Commons, says urgent action is needed.

She stated: “I have witnessed first-hand the incompetence and obstinance on display at HMRC and HM Treasury through my constituency casework. I have been promised callbacks that have not materialised; I have had to wait weeks and months at a time for responses to constituent enquiries; I have seen furlough money paid to businesses and then rescinded and clawed back the very next day – leaving workers with nothing.

“It’s imperative that HMRC gets its house in order, and fast.”

The call comes after one man, who has asked to remain anonymous, revealed how an HMRC operator told him the service would not start processing his application for a tax rebate – submitted in late August – until “on or around December 24”.

The man was seeking a refund of several thousand pounds in excess tax paid through the Construction Industry Scheme (CIS), which sees contractors deduct money from a subcontractor’s payments and pass this to HMRC as advance payments towards the subcontractor’s tax and National Insurance.

He was advised to file a hardship claim to get the money moving faster – something he says is urgent as rent arrears mount.

He told the Sunday National: “I was gobsmacked, I was shocked. I have no job because of coronavirus and everything just piles up. It’s an absolute nightmare. I go to bed with this on my mind, I wake up with the same thing.”

The Sunday National has learned of another firm left facing hefty repayments to HMRC through no fault of its own after the service overpaid support to it under Rishi Sunak’s Coronavirus Job Retention Scheme.

Last month Jim Harra, HMRC permanent secretary, told Westminster’s Public Accounts Committee that error and fraud in this scheme “could be between 5% and 10%” – which could mean as much as £3.5 billion of public money has been wrongly distributed. At the time, HMRC was probing 27,000 “high risk” cases and promised it wouldn’t “hesitate to take criminal action in the most serious cases”.

But those at the sharp end of delays and bungles want HMRC leaders to act now to stop more stress for struggling firms.

Jim Fairgrieve of NGM Accountants in Glasgow told the Sunday National problems such as those described above are “not uncommon”. He went on: “It’ll take HMRC three weeks to send a letter out, and when you get it the date is set for two weeks before it was sent. Things like that make it really difficult for the client.

“HMRC hold the gun. No-one wants to upset them because they think if they do they’ll be penalised. There’s a Big Brother effect – they can do what they like, when they like.

“It’s like the Johnson Government – nobody has any responsibility for anything and it’s always someone else’s fault.”

Furlough has protected 779,500 Scottish jobs – around 32% of the total workforce. On Friday, Sunak confirmed a new scheme aimed at protecting operations forced to close due to national or local restrictions over the winter. That Job Support Scheme will come into force on November 1 and cover two-thirds of an employee’s pay, but GMB union called it “insubstantial”, saying it would leave low-paid workers short.

HMRC said it could not verify the claims put to it by the Sunday National but “colleagues are currently working on returns made at the end of August”. A spokesperson said: “Customers in that category will receive money – if they are due it – asap.”

The representative also said while phone lines were “under considerable pressure” when the furlough scheme was announced in March, “we don’t recognise those waiting times currently. If individuals or businesses believe we made mistakes or caused unreasonable delays, complaints can be made online.”

Referring to the subcontractor, Thewliss said: “Cases like this are occurring all too often. Facing these kinds of delays in applying for things like tax rebates – simply in order to keep your head above water – is unacceptable. What is sorely missing here is a route by which urgent cases can be raised.”