Many people contacted about crucial changes to their mortgage support are yet to make their minds up about what to do - with just a couple of weeks to go - figures show.
From April 6, support for mortgage interest (SMI) will stop being a benefit and will instead become a loan.
SMI helps protect people in receipt of certain benefits from having their home repossessed, by contributing towards the interest payments on the claimant's mortgage.
Finance experts have called for the change to be delayed to give people more time to make an informed decision.
Figures released by the Department for Work and Pensions (DWP) show as at March 21, it has sent a letter about the new SMI loans scheme and attempted a follow-up phone call to 95% of SMI claimants.
Those not yet contacted include some people who have only very recently claimed SMI, those where DWP has no record of a valid telephone number and some cases where the claimant has appointed someone else to look after their interests.
Over half (51%) of claimants who communicated their intention to the DWP in a follow-up telephone conversation said they will decline the offer of an SMI loan.
Meanwhile a quarter (25%) are undecided and just under one quarter (24%) indicated that they would accept the loan.
Helen Morrissey, a personal finance specialist at Royal London, said: "With just two weeks to go many thousands of people risk losing vital mortgage support.
"Government must reconsider its approach and delay the implementation of this change to make sure people get the support they need to make an informed decision."
Royal London recently highlighted figures contained within the Office for Budget Responsibility's Economic and Fiscal Outlook which said around 10,000 claimants had so far agreed to take up the loan - compared with a figure of 100,000 which had been expected by the end of 2018/2019.
The DWP document said claimants who decline the SMI loan may change their mind and can have SMI payments backdated to April 6 - the date when the loan scheme will be introduced.