A UNION has accused Tesco of acting "unlawfully" by threatening to fire staff and cut pay over a strike which it is feared will mean it will struggle to fulfil its Christmas deliveries.

Trade union Usdaw (Union of Shop, Distributive and Allied Workers) has threatened to start a strike from December 20 at distribution centres including its biggest depot in Livingston - just as Christmas online orders are due to be shipped out.

But Scots workers at what is Tesco's largest distribution centre in Europe have raised concern that managers have sent threats to their jobs as well as withdraw strike pay and bonuses as staff are balloted over industrial action.

The UK's fifth biggest union Usdaw, which represents 400,000 workers in the retail sector, as well as people employed in transport, distribution, food manufacturing, chemical industry and other trades, are now taking legal advice over Tesco's threat to pay and jobs.

The union has told Tesco they believe the action is "unlawful" and have told the supermarket giant: "We reserve our members' legal rights on this matter."

Scots workers have received a letter from Andrew Woolfenden, the UK distribution and fulfilment director of Tesco issuing the warning after staff rejected an offer of a 4% increase on hourly pay rates.

He said that if strike action takes place and stock is not delivery in time to stores as a result "we put our business and the future of your site at risk".

He said that if they took part in strike action they will be in breach of their contract of employment and that they will not be paid for the entire shifts in which strike action is taken.

The letter states that if workers take part in strike action they may not be paid a colleague bonus for 2021. The average payment under the scheme was £801.

HeraldScotland:

The Livingston distribution depot

He warned they may also lose a warehouse market supplement of up to £500 and a driver market supplement of up to £800.

And he also warned that if strike continued for 12 weeks, "we may decided to terminate your employment with the company..."

He wrote: "You will lose more than you gain by taking strike action. Therefore if you are a union member and recieve a ballot paper, I would urge you to use your vote and vote 'no' to taking strike action."

National officer Joanne McGuinnes wrote in response: "You will of course be well aware of the difficulties you would face in being able to lawfully dismiss any member after 12 weeks of action whilst sustaining your operation. It is therefore very unfortunate that you... choose to make such a threat which is solely designed to deter members from taking lawful action."

Usdaw has told staff in a separate communication: "We are extremely disappointed that the Company has resorted to threatening to take money away from their hard working staff simply as a result of exercising their right to ballot for industrial action.

"We will be contacting the company to understand why they believe they have a legal right to make these threats and/or withhold these monies from our members.

"It is extremely important that we do not allow the company's tactics to influence the outcome of the ballot."

"The letter also includes reference to potentially terminating employment should the industrial action last longer than 12 weeks. Usdaw believes that taking such a step would not be in Tesco’s interests and would likely have a far more detrimental impact on their operation than the potential industrial action."

The row is centred around workers being given a "decent pay rise" to help cope with increased living costs being caused by inflation.

Usdaw members have already rejected one pay offer from Tesco and are being balloted on whether to strike in the week starting December 20.

The ballots will run until December 6. If the strikes go ahead, they will affect nine Tesco warehouses.

The Livingston distribution centre opened in May, 2008, serves all Tesco stores across Scotland and Northern Ireland and employs nearly 2000 people.

Apart from Livington, the strike threat also affects centres in Daventry, Goole, Hinckley, Lichfield, Magor (both trunk and main site), Peterborough and Southampton.

In February, Usdaw won a Court of Session court case stopping Tesco from moving staff at the Livingston distribution centre onto new contracts in what the union called a "fire and rehire" tactic.

The interim interdict from the Court of Session in Edinburgh meant that the supermarket at temporarily prohibited from unilaterally withdrawing an entitlement to 'retained pay' by terminating workers’ contracts and re-engaging them on new terms.

Usdaw claimed that the arrangement would have resulted in workers losing between £4,000 and £19,000 per year.

In April, Tesco announced a rise in sales but a sharp fall in full-year profits after spending nearly £900m to carry on trading through the Covid pandemic.

Tesco's full year pre-tax profit fell from £1bn to £825m.

Usdaw said that it had repeatedly made it clear to Tesco that they can avoid industrial action if they make an improved offer that is acceptable to staff.

The union told workers: "It is Tesco’s refusal to improve the offer that has brought us to this stage, and it is in Tesco’s power to avoid industrial action by taking the positive step of improving their pay offer, rather than the negative approach they have decided on.

HeraldScotland: People queue outside a Tesco Extra store in Madeley, Shropshire

"Tesco have made an implied threat in the short term through the potential loss of a non-guaranteed bonus. Usdaw is concentrating on maximising the pay offer and securing long term improvements to your contractual pay, that you will continue to benefit from for every hour you work in the future.

"It is, however, extremely important that we show a united front and deliver a clear and unambiguous vote in favour of industrial action to place maximum pressure on the company to improve their offer."

Mr Woolfenden told staff that the "fair and competitive 4% offer" was one of the highest one-year offers made in Tesco distribution for over 25 years. "This has been made in recognition of the extraordinary efforts of our colleagues throughout Covid-19," he said.

"It also reflects the impact of inflation as well as the competitiveness of the labour market for drivers and warehouse colleagues at this time.

"This offer represents a real-terms increase in your pay and will be backdated...

"Going beyond the 4% increase would not be sustainable and would prevent us from continuing to run the business efficiently which enables us to preserve and create jobs and invest in pay increases for the years to come."

The Unite union also said they were undertaking a nationwide strike ballot of 3,500 Tesco lorry driver and warehouse workers at the end of October due to the "offensive" pay offer at the Belfast, Didcot, Doncaster and Thurrock regional distribution centres.

Tesco customers who are signed up to its Delivery Saver service were able to book Christmas slots from 6am on November 16.

But shoppers expressing concern after they were placed in a queue of 300,000 people all trying to book their delivery.

Delivery Saver costs £7.99 per month and gives shoppers free deliveries on orders worth more than £40.

Other deliveries are charged a flat fee of £4.50, or £5.50 if you're ordering from a fulfilment centre.

A Tesco spokesman said: “Our distribution colleagues have worked tirelessly through the pandemic in order to keep products moving for customers. The pay offer we have made is a fair recognition of this, and is one of the highest awards made within our distribution business in the last 25 years, building on our highly competitive pay and rewards package. 

"We welcome the decision by our colleagues at the sites who have voted against industrial action. We are disappointed that some have voted to proceed, and we have contingency plans in place to help mitigate any impacts. We have worked hard to deliver Christmas for our customers and are confident we will be able to fulfil our plans.”