McDonald's staff at Crayford could go on strike in what would be a UK first for the fast-food restaurant.

Employees there, along with workers in Cambridge, have backed a call for industrial action amid concerns over working conditions and the use of zero-hour contracts.

The Bakers, Food and Allied Workers Union (BFAWU) said staff were demanding a wage of at least £10 per hour and more secure working hours, alongside the recognition of the right to form a trade union as employees of the company.

In a statement the BFAWU said: "Workers have found themselves living on low wages with no guarantee of hours.

"This has been viewed by some as punishment for joining a union, and has seen employees struggle to meet their rent payments, whilst some have even lost their homes."

The UK National Living Wage stands at £7.50 for workers aged 25 and over, and £7.05 for those aged 21 to 24.

McDonald's staff in America are leading a campaign to be paid 15 US dollars (£11.65) an hour, supported by the Service Employee's International Union.

Ian Hodson, BFAWU national president, said: "We, at the BFAWU, fully support the historic decision by these brave McDonald's workers to stand up and fight back against McDonald's - a company that has let them down one too many times.

"McDonald's has had countless opportunities to resolve grievances by offering workers a fair wage and acceptable working conditions. This is a call for change."

McDonald's, which employs around 85,000 staff in the UK and one million worldwide, announced in April that workers would be offered a choice of flexible or fixed contracts with minimum guaranteed hours.

The move followed trials in 23 restaurants, which will be extended to 50 more sites before rolling out nationally across the year.

It also promised by May that hourly-paid workers will have received an average hourly pay increase of 17 per cent over the past two years.

A spokesman for McDonald's said: "We can confirm that, following a ballot process, the BFAWU have indicated that a small number of our employees representing less that 0.01 per cent of our workforce are intending to strike in two of our restaurants.

"As per the terms of the ballot, the dispute is solely related to our internal grievance procedures.

"We are proud of our people at McDonald's, they are at the heart of all we do and we work hard to ensure that our teams are treated fairly.

"Our internal processes underpin that commitment."