M&G, Invesco, GAM, EdenTree and Legal & General, which all hold the Aviva and General Accident preference shares that had been threatened with cancellation, have written to economic secretary to the Treasury John Glen urging him to take action.
The fund groups were instrumental in forcing Aviva's climbdown, having met with chairman Adrian Montague to urge him against the move.
After Aviva backed down, the fund groups urged other preference share issuers to reinforce the 'true irredeemable nature' of the investments in their documentation.
Barring Ecclesiastical Insurance's statement reassuring investors, issued just day's after Aviva first made its cancellation threat, issuers have not been forthcoming.
Writing on behalf of the fund groups, Rupert Krefting, M&G head of corporate finance and stewardship, urged the Treasury to amend the Companies Act 2006 to protect preference shareholders from similar moves.
'Although Aviva has decided not to pursue its action to repay its preference shares at par, the issue has highlighted the legal uncertainty surrounding the rights of preference shareholders, and indeed other classes of shares, which are in a relative minority compared to ordinary shareholders,' he said.
'Attempting to persuade all issuers of preference shares to change their articles of association does not solve the fundamental issue that the basic rights of a shareholder asset class should be easy to establish and be transparent.
'We therefore urge that HM Treasury, the Treasury Committee and the Financial Conduct Authority look, with a matter of urgency, at closing the legal loophole in the Companies Act 2006 that has allowed this situation to develop.'