Tenants in London’s Heron Tower are said to be unhappy after it was revealed that the skyscraper will be renamed Salesforce Tower London last week.

A handful of businesses based in the City of London’s tallest skyscraper have reached out to their lawyers in a bid to avoid the proposed rebranding, according to The Times.

Powa Technologies, which operates in roughly the same space as Salesforce, is said to be unhappy that the deal was reached without consulting the existing tenants.

Powa moved into Heron Tower last December and it is reported that it would not have done so had it known it was about to be named after a rival.

Landmark Plc, which services the Heron Tower offices, told The Times that it was “reviewing its options” after receiving complaints from clients who rent the office space that it manages.

The controversy comes after Heron International announced last Thursday that it had struck a 15-year naming rights deal with CRM cloud software giant Salesforce.com.

Salesforce, which is also spending $700 million (£415 million) on a new HQ in its hometown of San Francisco, California, is taking an additional 50,000 sq ft in the 46-story building. 

In a letter that was hand-delivered to tenants, Gerald Ronson, CEO of Heron International, which built and owns the building, said: “As part of the agreement, Salesforce.com has agreed to pay all reasonable costs associated with the reprinting of your company’s stationery and business cards and related amendments you may need to make to your websites to reflect this change.”

Several tenants are reported to have emailed Landmark MD Richard Gill asking if the rebranding was an April Fool’s joke when they were first notified.

Other tenants were more accepting of the change, with global recruitment consultancy and IT outsourcing provider Harvey Nash saying  it was “fairly relaxed about the change”.

Heron International declined to comment.