Carmaker Jaguar Land Rover (JLR) has confirmed that output at some of its manufacturing sites will resume on Wednesday, as it continues to recover from a serious cyber-attack.

Its production lines have been at a standstill since the start of September, following the attack.

The phased return of staff will begin at some sites in the West Midlands and Merseyside.

JLR has also announced a programme to fast-track payments to its direct suppliers, some of which had laid off workers after their revenues dried up following the hack.

Initially the scheme will be confined to the most critical suppliers needed for restarting production, but it will be expanded at a later date.

JLR says the phased restart will begin at its Wolverhampton engine plant in Wolverhampton and its battery assembly centre in Hams Hall.

Employees who work in facilities which prepare pressed metal bodywork at the company’s sites in Castle Bromwich, Halewood and Solihull will also be brought back in – as will those who work in the Solihull car plant’s body shop and paint shop.

JLR says this move will be “closely followed” by the resumption of vehicle manufacturing in Nitra, Slovakia. The Range Rover and Range Rover Sport production lines in Solihull are expected to restart later in the week.

It is not yet clear when output will resume at JLR’s Halewood plant on Merseyside.

Experts have warned that it is still likely to be several weeks before the production lines are running as normal.

JLR has also outlined an accelerated-payment scheme to help its suppliers, many of whom have been struggling financially.

So-called Tier 1 suppliers, with which the company has a direct relationship, will be able to get paid for new orders shortly after they have been placed, rather than up to two months after delivery. JLR says this will enable them to get funding up to 120 days earlier than normal.

There is an expectation that these companies will then offer similar terms to their own suppliers, allowing funding to flow rapidly down the supply chain.

The scheme is being funded by JLR itself, using credit provided by a commercial bank. It is not linked to the £1.5bn loan guarantee recently offered to the carmaker by the government.

Industry insiders have warned that the resumption of production, while welcome, does not end the crisis being experienced by many smaller suppliers. Some are heavily reliant on JLR and have had little or no income for the past month and a half, while bills have still had to be paid.

Last week, one leading contractor told the BBC that the help offered by the government so far was inadequate.

David Roberts of Evtec Group said: “We asked the government directly, at ministerial level, to directly support the sector. They listened, but they did nothing. It’s almost like they’ve turned a deaf ear to the needs of advanced manufacturing.”

Another supplier, Genex UK, a small company which presses metal parts, told the BBC it had been forced to lay off 18 staff because of a cash shortage.