The restaurant chain Wahaca has been forced to change its policy, after a waiter was told he would have to pay part of the bill when customers left without paying.

The former Labour leader of Camden council Sarah Hayward contacted the company on social media on Saturday 15 June after hearing of the policy, saying: “Hi @wahaca just eaten in your Kentish Town restaurant for the last time. Ppl next to us left without paying and their server is made to foot the bill from his wages. Apparently company policy. Utterly shameful employment practice.”

The post has been retweeted more than 8,000 times, and the waiter has been assured he will not have to cover the costs of the bill.

Wahaca said the incident was caused by an “internal communications issue” and that it had demonstrated the need for “clarity over the policy”.

The new policy will ensure that a waiter is not financially responsible for a bill if a customer walks out, but will be investigated if there is reason to suspect the waiter was complicit in the walkout.

The company said: “In light of the recent incident where customers walked out of one of our restaurants without paying, we realise that our policy on how to deal with this has not been clear enough and we apologise to our teams for this.

“We subsequently contacted all of our teams to clarify this and to ensure that waiters will not have to pay in the unfortunate times when this occurs.

“In situations of a walkout, whilst the waiter is responsible for the table they will not have to pay any element of the bill. However, if the manager suspects that the waiter was complicit in the walkout then there should be a full investigation which will be taken to the operations manager to decide the appropriate action.”

In a separate statement, Mark Selby, the owner of Wahaca, said: “In no way would an individual be responsible for covering the bill in a situation they had no control over. As a business, we prioritise our staff and do everything we can to ensure our teams are well looked after at work.”

Previously, company policy dictated that individuals should only be responsible for an unpaid bill in cases where “real negligence” had occurred – for example allowing a customer to leave knowing that they had not paid.

A spokesperson from Unite the Union said that while the policy was shocking, it seemed to be standard industry practice.

“This sort of behaviour is wage theft and it is just the tip of the iceberg because companies will say it is just the actions of individual managers, but those managers are given leeway to behave that way. But a manager only thinks they can do that because they think they’re following policy.

“It is wrong, it is bad practice and it has got to stop,” she said.

She also warned that in cases where deductions come from low-wage staff members, the policy could also be in breach of the Minimum Wage Act.

