Foreign Secretary Dominic Raab was confronted by an angry mother at a local hustings event as she questioned him about Conservative plans to raise the threshold for paying National Insurance.
The unnamed mother, who said she was a foodbank user, asked him about the suggestion it would "put £500 in the pocket of everybody", questioning him how far that money would go.
Mr Raab replied: "It's an incremental increase but it's more than any other party is offering to the lowest paid in our society. I would raise it even further."
However, when asked how the plans would be funded, Mr Raab said "I've done this for two hours", before eventually walking away.
The angry parent told him: "I just want to understand. I am a foodbank user and I don't think you've really stepped in one. I don't think you've talked to the people there.
"When you are talking about the £500 I think you are being offensive to the people who actually need to use the foodbank. When you are talking about three weeks of your shopping per year."
The confrontation took place on Thursday at St Andrew's Church in Cobham.
At the same event, Mr Raab was booed and laughed at by a room of constituents as he explained his party's Brexit plans.
He was taking questions from his constituents alongside Monica Harding, the Liberal Democrat hopeful.
As Mr Raab tried to give his closing speech, there was continued heckling from the crowd.
Saira Ramadan, who caught both moments on camera, told the PA news agency: "Mr Raab said that he had been 'doing this for two hours' when this lady wanted to discuss the Tory pledge with him and he immediately left the church after saying 'well you're entitled to your opinion' at the end of the video.
"Frankly, I was disappointed that he appeared to give her relatively short shrift. As her MP, there for a public speaking event, I would have expected him to give some time to one of his more vulnerable constituents.
"I appreciate that the nature of her question was somewhat hypothetical and he may have found it difficult to give an appropriate response but the manner in which he responded to her was unbecoming of someone of his standing."