People may be able to donate money towards the cost of making Big Ben chime when the UK leaves the EU, Boris Johnson has said.
The prime minister told BBC Breakfast that getting the famous bell to ring at 23:00 GMT on 31 January would cost £500,000, but said some form of crowdfunding might be possible.
The bell was temporarily silenced in 2017 for refurbishment of the tower.
A bid to get the bell-ringing enshrined in law was dismissed last week.
An amendment to the PM’s Brexit bill, which would have required it to chime on Brexit day, was not selected for a vote in the House of Commons.
“We’re working up a plan so people can bung a bob for a Big Ben bong, because there are some people who want to,” Mr Johnson said on Tuesday morning.
“Because Big Ben is being refurbished, they seem to have taken the clapper away, so we need to restore the clapper,” he added.
“And that is expensive, so we’re looking at whether the public can fund it.”
The House of Commons Commission, which manages the parliamentary estate, said the extra spending could not be justified, but it would listen to MPs on the matter.
The body heard that for the bells to chime, a temporary mechanism used on Remembrance Sunday and New Year’s Eve would have to be restored to the Palace of Westminster’s Elizabeth Tower, and a temporary floor of the belfry installed.
‘£50,000 a bong’
Costs for this work, alongside testing and ringing the bell, were estimated at approximately £120,000. In addition, existing restoration works would be delayed by two to four weeks, at a cost of £100,000 per week.
Authorities said the £320,000 minimum cost could therefore rise to £500,000.
Commons Speaker Sir Lindsay Hoyle said: “The Commission believes it is important to weigh up the costs this would involve if Big Ben is to chime on 31 January.
“You are talking about £50,000 a bong. We also have to bear in mind that the only people who will hear it will be those who live near or are visiting Westminster.”
Clock restoration expert Paul Kembery said a temporary platform and electric motor had been used to chime the bell on Remembrance Sunday and New Year’s Eve.
But he told the BBC’s Victoria Derbyshire programme that with only just over two weeks to go, there was probably not enough time to put both back in, even if the public raised the required funds.
Brexiteer Mark Francois, one of the Tory MPs behind the bid to legislate for the Brexit day bongs, has said it would be “inconceivable” if Big Ben did not sound to mark the occasion.
“As we leave at a precise specified time, those who wish to celebrate will need to look to a clock to mark the moment,” he added.
But Labour MP David Lammy said £500,000 was a “huge amount of money to waste on jingoism”.
“I am not fussed about whether Big Ben bongs on Brexit day […] what I care about is the £130bn and counting that leaving the EU has already cost,” he tweeted.