Almost 100 workers have walked out of the firm that supplies fresh food for Marks & Spencer.

The Bakkavor staff have been in dispute with bosses for months over a wage rise that has been described as a "poverty pay offer".

The GMB union said the offer of a 2.27% rise would leave the majority of workers at the company's two Bo'ness sites on £8.21 an hour - 79p less than the recognised living wage of £9.

Concerns of management intimidation and union-busting tactics have also been raised, a GMB spokeswoman said.

In addition to this week's action by night shift workers, three further walkouts are planned in the coming weeks.

Christina Lambie, GMB Scotland organiser, said staff were barely paid enough to make ends meet.

"Bakkavor's refusal to negotiate a decent pay offer means the sites in Bo'ness are the epitome of poverty pay employment - it is a disgrace this company has marooned the majority of staff on the absolute hourly minimum.

"The strike will affect the production and distribution of fresh food to M&S shops across the country, but that lucrative contract and the profits it generates for this food manufacturing giant, which boasts global revenues of £1.85 billion, demonstrate why the Bo'ness staff deserve better.

"Make no mistake that it is not an easy decision for our members to forego their pay and take strike action, but they have been left with little choice by an employer who has consistently failed to recognise their desire for a decent pay offer that tackles the basic cost of living."

She added: "They deserve not to have to reply on food banks. They deserve to be able to pay their bills.

"They deserve to be able to go to Marks & Spencer once in a while."

Bakkavor declined to speak to STV News but in a statement claimed their pay levels were "highly competitive" and the firm was committed to paying the national minimum wage.

An M&S spokesperson said: "We're working closely with Bakkavor and have contingency plans in place to ensure our supply isn't affected."