Donald Trump is trying to make voting dangerous in order to deter opponents and ensure his own reelection, the Democrat who led the impeachment inquiry against him has said.

Adam Schiff, chairman of the House intelligence committee, spoke out a day after the president said people who voted by mail were often "cheating" and that everyone should turn up to vote in person and with picture identification – despite the coronavirus pandemic raging across the country.

Mr Trump made the comments when asked whether in-person voting should go ahead in the Wisconsin primary election on Tuesday, despite efforts by the state governor to switch to all-mail voting.

Other primaries being held this month – in Alaska, Wyoming, Puerto Rico and Ohio –have switched to mail votes but Republicans in Wisconsin have resisted efforts to do so in one of the states that proved crucial to the president's victory in 2016.

Asked about the issue at his daily White House coronavirus briefing on Friday, the president claimed the Wisconsin issue was really about Mr Trump having endorsed a conservative judge, but went on to say he did not believe mail voting should be used in the election cycle up to his reelection bid in November.

He said: "No, because I think a lot of people cheat with mail-in voting. I think people should vote with ID - voter ID. I think voter ID is very important. And the reason they don't want voter ID is because they intend to cheat.

"When you get something, when you buy something, you look at your cards and credit cards and different cards - you have your picture on many of them. Not all of them, but on many of them. You should have a picture on your - on your - for voting. It should be called 'Voter ID'. They should have that. And it shouldn't be mail-in."

He added: "It should be: You go to a booth and you proudly display yourself. You don't send it in the mail where people pick up - all sorts of bad things can happen by the time they signed that, if they sign that - if they signed that by the time it gets in and is tabulated.

"No, it shouldn't be mailed in. You should vote at the booth. And you should have voter ID, because when you have voter ID, that's the real deal. "

Republicans regularly support voter ID claiming it will reduce electoral fraud. However, critics say there is little fraud in US elections and that voter ID is part of a wide-ranging plan to try to exclude potential Democratic voters, particularly poorer people who might struggle to get hold of the necessary documents. Republicans are also accused of trying to limit the votes of poorer people by closing voting stations and denying votes to people convicted of criminal offences.

Mr Schiff, who led the impeachment inquiry against the president in the House, and then argued the case in the Senate, criticised the president's comments.

Mr Trump was impeached by the House on charges of abusing his powers and obstruction after he tried to pressure the Ukrainian president to interfere in the 2020 election by announcing an investigation into the likely Democratic candidate, Joe Biden.

On Saturday morning Mr Schiff tweeted: "After being caught trying to cheat in the next election, Trump opposes vote by mail over concerns about 'cheating'.

"Nonsense. He prefers making voting dangerous for millions of Americans if it helps his re-election.

"Every American must be able to cast a secure ballot by mail."

On Friday Mr Trump said he expected the general election to go ahead on 3 November as planned.

The president has repeatedly claimed that three million of the votes against him – the number by which Hillary Clinton beat him by in the popular vote – were cast illegally, although he has so far been unable to provide any evidence for this.

Before the election he claimed that if he lost it would be because the other side had cheated.

He has also disputed assertions from his intelligence chiefs that Russia interfered with the 2016 election in order to cheat on his behalf. At a press conference in Helsinki in 2018 with Vladimir Putin, he said that he believed the Russian president's assurance that Moscow had not been involved.