A former minister has questioned the legitimacy of the EU referendum after allegations of attempted Russian influence over the Brexit process.
Labour's Lord Foulkes of Cumnock said the "disturbing reports" cast doubt on the credibility and legitimacy of the referendum outcome.
But Brexit minister Lord Callanan dismissed his claims, advising the peer not to believe everything he read in the media.
The question time exchange came after it was reported that more than 400 fake Twitter accounts believed to be run from Russia had published posts about Brexit.
Lord Foulkes asked the minister if he had seen "the disturbing reports in the media today that the Russian government has been using data transfer through social media to influence the outcome of the EU referendum in favour of the Leave side.
"Doesn't this not now cast doubts about the legitimacy and credibility of that referendum," he demanded.
"That referendum can no longer be considered to represent the will of the British people."
Lord Callanan told him: "Unsurprisingly you will find that I don't agree with you.
"You shouldn't necessarily believe everything you read in the press and the media."
Tory former cabinet minister Lord Forsyth of Drumlean said it was high time that Liberal Democrat and other peers accepted "the decision of the British people and joined Team UK and started arguing for the interests of our country rather than against it".
Lord Callanan said Lord Forsyth was correct, adding: "It would be nice to think opposition peers would be in favour of getting a good deal on behalf of the UK.
"I assume they are all democrats and would want to respect the result of the referendum."
Tory Lord Cormack said: "To state the facts and question how we are tackling the European negotiations isn't to be unpatriotic."
Lord Callanan agreed that questioning matters of policy and tabling amendments to legislation was not unpatriotic but the "duty of parliamentarians".