Jaguar Land Rover suppliers are bracing for cyberattack-related factory disruption to last beyond Christmas as the government races to measure the fallout on Britain’s automotive sector.

Some bosses in the supply chain have now largely discounted production at the UK’s biggest carmaker being fully back up and running after being told that JLR has still yet to get to the bottom of a hack that has crippled global operations.

JLR is understood to be running a number of scenarios to restart its factories with sources stressing that other options envisage a far shorter timeline.

Senior industry figures within the supply chain are working on a timeframe of at least 11 more weeks before JLR’s factories are back to normal under one of the scenarios.

They have pencilled in a further four weeks to diagnose the problem and either reset or rebuild the carmaker’s complex array of computer systems. Three weeks of testing alongside “dummy suppliers” would follow to ensure that the business was free of bugs related to the hack. After this it would take a further four weeks to ramp back up to full capacity.

JLR’s global operations were brought to a standstill on September 1 after falling victim to a cyberattack. The carmaker employs 30,000 people directly and supports a further 200,000 UK jobs in the supply chain. The company and its advisers have been working around the clock to rectify a problem that is extremely complex.

Ministers are now scrambling to ascertain the impact on one of Britain’s most important manufacturing sectors amid fears that Labour’s industrial strategy — a lynchpin of promises to boost economic growth — could be undermined.

Prime Minister Keir Starmer speaks to the media about a US-UK trade deal.

Sir Keir Starmer has visited Jaguar Land Rover factories to showcase his industrial strategy

DARREN STAPLES/EPA

Government sources this weekend said that officials from a number of departments are mapping out JLR’s supply chain to understand where taxpayers may need to step in.

Patrick Hosking: Why should taxpayers pick up bill for Tata’s cyberattack?

Among the parameters being assessed are the dependency of each supplier on JLR, the state of their finances, and how many staff have been sent home on unpaid leave.

Suppliers are facing a critical week with the first major squeeze on cash flows since the crisis began. Quarterly rent payments are due this week and, for many, monthly payroll and PAYE are payable on Friday.

The impact of JLR’s cyberattack is also putting pressure on car dealers. It is understood that larger operators have now found a workaround that allows them to access vehicles held for sale and register them. But the biggest issue is locating spare parts, which is largely a manual process involving written paperwork, said a source at one large dealership chain.

JLR has set up a dedicated supplier helpline for companies affected by the cyberattack to discuss how the carmaker can provide support to them.

Chris McDonald, the industry minister, said: “We have two priorities — helping Jaguar Land Rover get back up and running as soon as possible, and the long term health of the supply chain.

“The ongoing shutdown at JLR is of huge concern to both those employed by the firm and its vast supply chain which stretches across the Midlands and the northwest with hundreds of companies impacted.

“The government provided immediate support to help the company understand the attack and how best to recover from it. We are acutely aware of the difficulties the stoppage is causing for those suppliers and their staff — many of whom are already taking a financial hit through no fault of their own.”

On Friday, government officials attended an emergency meeting convened by trade body the Society of Motor Manufacturers and Traders (SMMT) to consider the impact of the JLR cyber incident on the wider supply chain.

A spokesman for JLR welcomed the intervention. “This is an important move to further identify the challenges that businesses are facing following the recent cyber incident at JLR.

“[It] complements JLR’s wider response, including our focus on our global supply chain, our retail partners, our clients and our people as we continue to work around the clock to restart our global applications in a controlled and safe manner.”