The company said customers would feel "no effect" by action

More than 500 members of the GMB union at the distribution centre in Washington are taking part in the action which began at midnight.

The GMB said the strike would be "solid" and impact stores across the north of England.

But an Asda spokesman said customers would not "notice a thing" and that contingency plans were in place.

The walkout is due to last 72 hours, after members were balloted and rejected the pay offer.

A union spokesman told BBC News ahead of the action: "We are available for talks until the 11th hour to discuss the issues."

'Great offer'

GMB organiser Michael Hopper added: "The strike will be solid and will impact on Asda stores across the north of England.

"Asda will have to improve its offer. The company need to get back to the negotiating table and sort out a deal with the members."

The union said its 530 members had been offered a 10% pay rise, but only if they gave up the right to collective bargaining, which they refused.

An Asda spokesman said the distribution centre dealt with about 6% of non-fresh food so the company had been able to make contingency plans and "customers would not notice any difference".

He added that the company had been in touch with the union by letter and was happy to work with them and with arbitration.

The spokesman said: "The offer that was made was a great one and well above the rate of inflation.

"We have an open door policy and any staff members who want to discuss the situation face to face are welcome."