Recent research by My Mortgage Direct found that only one in five borrowers has taken out the insurance along with a mortgage in recent times.
Commenting on the findings, Mr Firmin said there is "never a better time" to consider buying the insurance than when taking out a home loan, as otherwise people may not ever get it.
He added: "We're always going to advocate independent advice, particularly for things like critical illness cover and income protection [where] there's a wide cost band."
Plan Insure is operated by the Plan Invest Group, which provides consumers with advice on a number of financial products, including investments, pensions and life assurance.
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