Ministers appear unlikely to make the forthcoming extra bank holiday in honour of the Queen’s platinum jubilee permanent, as Downing Street poured cold water on the plans and emphasised the high cost to the economy of such a move.

Business leaders – including the Dragons’ Den star Deborah Meaden and ITV’s chief executive, Carolyn McCall – had launched a campaign calling for the government to consider the wider benefits of turning next month’s additional public holiday into an annual fixture.

Others who backed the Friday 3 June “thank holiday” being repeated every year included the Confederation of British Industry, Hospitality UK and the archbishop of Canterbury.

The prime minister, Boris Johnson, and the chancellor, Rishi Sunak, were urged to consider the proposal, but No 10 suggested they were not likely to endorse it.

Johnson’s spokesperson said it was a “unique” event, and added: “I’m not aware of any plans to make it permanent.” He said each bank holiday “presents a considerable and significant cost to our economy and therefore each proposal would have to be considered carefully on that basis”.

While it would be kept under review, the spokesperson said a new bank holiday was estimated to cost the economy £2bn.

However, the government’s official impact assessment suggested there could be a boost for the hospitality, tourism and retail sectors, while also recognising that there could be benefits for mental health and wellbeing.

Campaigners said that research they commissioned from the accountancy firm PwC showed the government’s existing figures overestimated the potential cost of a new bank holiday by 64%, while failing to account for positive social and health benefits that were not captured by GDP figures.

Meaden said the extra bank holiday would help those businesses that struggled most during the Covid pandemic. She said: “We all have fond memories of trips away, gatherings with friends, or just enjoying some relaxing time with loved ones. But it’s also a major boon for many businesses – especially those sectors that have struggled during the pandemic.

“I’m backing the campaign because I think it will be a fitting tribute to Her Majesty’s 70 years of public service, and that of all the people who make our communities kinder, nicer places to live. But I also think the ‘thank holiday’ will provide the country with a social and economic stimulus we need after a difficult few years.”

Before the Covid pandemic, the largest monthly declines in GDP were at the time of the Queen’s golden jubilee in 2002, when output fell 2.2%, and 2012 diamond jubilee, when it fell by 1.5%.

To mark this year’s bank holiday to celebrate the Queen’s 70-year reign, opening hours for pubs and bars will be extended in England and Wales, with the close of 11pm being pushed back to 1am.

A new 50p coin has also been made available at post offices to mark the anniversary, with the maximum mintage said to be capped at 5,000,070.