The move, announced by Webb over the long weekend, means from 2016 the government will scrap claims on contributions made by a spouse under the married person’s allowance. Therefore, after 2016, spouses living overseas will no longer be entitled to receive state pensions based on their partner’s national insurance.

Nigel Green, chief executive of the deVere Group, said: “The government clearly needs to shore-up the country’s finances but there must be another way that it can boost its coffers rather than withdrawing, generally, much-needed pensions from widows, whose spouses have, most likely, contributed for many decades.

“Why should these people, whose husband or wife has died, suddenly be deprived of their entitlements because the country is now in the depths of a pension crisis?

“This policy – which was cynically framed by the pensions minister as stopping foreign citizens many of whom ‘have never set foot in Britain at all’ from claiming what they are not entitled to – will be extremely costly to enforce, will save the Exchequer relatively little, and is, many suspect, simply an ill-conceived knee-jerk reaction to UKIP’s recent successes.

“I would urge the government to stop tinkering with the pension system as the seemingly constant changes undermine the public’s confidence in the philosophy of putting money aside for one’s later years.”

Pension consultant Ros Altmann added: “In the rush to appease UKIP supporters, it would be really wrong for ministers to suddenly change the rules and take away pension rights from older women in the UK who were disadvantaged due to past circumstances not of their own making.  Yes, change is needed, but it must be managed in fair and carefully considered manner.”