Andrew George, MP for St Ives, was among nine rebel Liberal Democrats to vote against proposals for a three-year cap on most working-age state benefits.
But ahead of the Commons vote on the Welfare Benefits Up-rating Bill, which the Government won, Mr George argued more than one-third of benefits go to people with above-average incomes.
"Indeed, a former constituent of mine has said how laughable it is that he now lives in Greece yet still receives a winter fuel allowance," Mr George told MPs, adding later it took him two winters to spend the hand-out.
"Surely we can find savings that are less painful than those proposed."
By raising benefits by 1% until 2016 – rather than pegging increases to inflation, meaning claimants can expect a real-terms freeze – the Government expects to save more than £2 billion.
Official figures show nearly £13 million in winter fuel payments went to pensioners living abroad, including warmer climes such as Spain, Italy and Cyprus.
The winter fuel payment is given at a flat rate of up to £300 regardless of a person's wealth.
In response, Work and Pensions Minister Steve Webb joked the Cornwall MP's ex-constituent is "in our sights. All I can say is that I hope he enjoyed his last payment".
He added: "Joking aside, even if we took away all winter fuel payments to overseas pensioners, we would be talking about tens of millions of pounds, not savings on the scale that we need."
Mr George, who claims his amendment to the Bill to link benefit increases to average wages was blocked by Labour, argued the reform was unfair given the volatile inflation forecasts in areas including food and housing costs.
He said afterwards: "This risks leaving some of the poorest working and non-working households in dire circumstances. I believe that there could be less painful ways of helping the Government achieve its deficit-reduction programme."
Among the Lib Dem rebels was Adrian Sanders, MP for Torbay. Lib Dem leader Nick Clegg has warned Britain's continued fiscal crisis means all parties will have to admit to voters at the next election that benefits for all pensioners are no longer affordable.
The Deputy Prime Minister also suggested David Cameron's manifesto promise to retain universal pensioner benefits is "completely irrational". Another target could be the older person's bus pass, another non means-tested benefit.
