The timetable for a planned ban on pensions cold calling to be in place will be delayed until later this year, the Government has confirmed.
It was hoped legislation could be completed by the end of June, but the Treasury has now said there will soon be a short consultation to make sure the rules are "robust".
Regulations will then be laid before Parliament this autumn.
Pensions experts described the news as "hugely disappointing". saying savers continue to risk being targeted by scams which start with cold calls.
They urged the Government to put a ban into place quickly.
A Treasury spokesman said: "We're committed to introducing a ban on pensions cold calling as quickly as possible.
"Following debates in Parliament, and having considered evidence from the industry, we will launch a short consultation on the draft legislation to ensure it is as effective and robust as possible.
"We intend to lay the required regulations before Parliament this autumn."
Sir Steve Webb, a former pensions minister who is now head of policy at Royal London, said: "It is totally unacceptable that the Government has introduced yet more delay."
He continued: "In the meantime, thousands more people will be scammed out of their life savings."
Baroness Altmann, another former pensions minister, said: "The need for a ban is widely recognised.
"The sooner cold calling for pensions is outlawed, the sooner people will be better protected against being scammed and losing their life savings.
"So many people have already suffered from such pension frauds, and they almost all start with a cold call."
She continued: "Anyone who receives unsolicited approaches offering help with their pension - whether a call, text, or email - should steer well clear.
"Official or bona fide firms will not call you out of the blue and those friendly salespeople could cost you much or all of your pension.
"I urge the Government to ensure these regulations are ready and enacted very quickly."
Tom Selby, senior analyst at AJ Bell, said it is "hugely disappointing that the cold calling ban faces further delay".
He said: "Too many savers have already been fleeced out of their hard-earned retirement pots by scammers, with cold calling one of the main tactics employed."