The minimum starting wage for employees at Amazon.com Inc.’s UK operations was increased on Wednesday by up to 50 pence to between 11 and 12 pounds ($13.50) per hour. This move infuriated the company’s union, which had called for a larger increase.

A few days have passed since hundreds of employees at an Amazon (NASDAQ:AMZN) warehouse in Coventry, central England, staged the latest walkout in a pay dispute this year.

Almost 500 Amazon employees are represented by the union GMB, led by senior organiser Amanda Gearing. “We’re listening to Amazon workers and the message is very clear: this new pay rate is an insult,” she said.

“So, in response we will be consulting over the next few days and announcing a new wave of action.”

According to the union, the Amazon Coventry employees are asking for 15 pounds per hour to deal with a cost-of-living crisis that has provoked strikes in various industries in Britain over the past few months.

The new hike comes after Amazon increased UK hourly salaries by 50 pence to 10.50 and 11.45 pounds per hour last year. It will depend on locations and begin in April.

Amazon stated that its minimum wage has increased by more than 37% since 2018 and by 10% over the previous seven months.

In January, Amazon, which has 70,000 workers in the UK, announced plans to shut three warehouses in Britain this year, affecting 1,200 jobs, but said workers would be allowed to transfer to other units.

Those include three older British warehouses in Hemel Hampstead, Doncaster, and Gourock.