COLD callers will no longer be able to hide or disguise their phone numbers due to a new law being introduced next month.

From Monday, May 16, all marketing companies based in the UK will need to display their phone number when making unsolicited calls, even if their call centres are based abroad.

Baroness Neville Rolfe, minister responsible for data protection, said: "Nuisance calls are incredibly intrusive and can cause significant harm to elderly and vulnerable members of society.

"We’re sending a clear message to rogue direct marketing companies. Nuisance calls are unacceptable and we will not hesitate to take action against the companies behind them."

Companies can risk fines of up to £2.5million from regulators if they continue to bombard consumers with unwanted calls.

Richard Lloyd, executive director of consumer group Which?, said: "This is another important victory in the fight against nuisance calls.

"With marketing firms now being forced to display their numbers when making calls, it will make it much easier for people to report them and enforcement action to be taken when companies break the law."