A voter registration site that crashed in the run-up to last year’s EU referendum could have been targeted by a foreign cyber attack, MPs say.
The “register to vote” site crashed on 7 June last year just before the deadline for people to sign up to vote.
The UK government and electoral administrators blamed a surge in demand after a TV debate.
But MPs on the parliamentary public administration committee say a foreign cyber attack could not be ruled out.
The committee’s chairman, Leave-supporting Conservative MP Bernard Jenkin, told BBC News there was no “hard and fast” evidence the registration site had been targeted.
But he said the committee’s report had included the possibility that the crash “may have been caused by a DDOS (distributed denial of service attack) using botnets” in its report “on advice”.
He declined to elaborate further.
The then Prime Minister David Cameron extended the deadline for registering to vote in the referendum after the website crashed.
The committee has also criticised Mr Cameron’s “questionable” motives for calling a referendum in the first place, saying it had been done to “call the bluff” of his critics and shut down “unwelcome” debate.
The committee urged future governments to think carefully before promising nationwide votes on controversial issues, particularly if they are not prepared to implement an outcome they do not like.
“There was no proper planning for a Leave vote so the EU referendum opened up much new controversy and left the prime minister’s credibility destroyed,” the report says.
It said that civil servants should be required to prepare for both possible outcomes in future referendums – such as a second vote on Scottish independence – something they had been prevented from doing in the run-up to the Brexit vote.
The committee called on the government to set up a new Cyber Security Centre to monitor and contain potential attacks on UK elections and referendums – particularly foreign attempts to influence public opinion and disrupt the democratic process.
“The US and UK understanding of ‘cyber’ is predominantly technical and computer-network based,” said the report.
“For example, Russia and China use a cognitive approach based on understanding of mass psychology and of how to exploit individuals.
“The implications of this different understanding of cyber-attack, as purely technical or as reaching beyond the digital to influence public opinion, for the interference in elections and referendums are clear,” the report added.