Charities have urged Boris Johnson for more funding and changes in legislation - or face losing several health projects which ease the strain on the NHS.
The Health Lottery has united with other charities in the campaign to continue to help good causes across the UK.
Currently, The Health Lottery jackpot never reaches £1,000,000 despite years of lobbying by charities for this to be changed.
"This funding is under threat. Outdated legislation limiting the size of society lottery jackpots, leads to fewer tickets being sold. This means less money for good causes," said a spokesman for the charity today.
"Had the UK government allowed £1,000,000 jackpots since lobbying began in 2013, an estimated additional £150 million could have been raised for charity.
"Many of those projects are now working hard to reduce the burden on the NHS."
The charity says several MPs, including Karen Bradley, Tracey Crouch and Jeremy Wright, have backed its argument but Boris Johnson is yet to indicate change.
The Lotteries Council, which is the trade association representing the needs of all society/charity lotteries, also says caps should be removed from charity jackpots and that this would lead to more ticket sales.
It stresses The Health Lottery is significantly different from the National Lottery and, often, players choose to compete in both.
These sentiments have been shared in parliament in recent years.
Giving oral evidence to the House of Commons, Public Accounts Committee in January 2018, Sue Owen, Permanent Secretary at the Department for Digital, Culture, Media and Sport said: “It is important to note that the different bits of the lottery are not competing, we don’t think, against each other.
"Many players do both. Half the Lotto players also play other games and, of the ones who play scratch cards, I think about a quarter also play the lottery, so we don’t think the different games are cannibalising each other.”
The Health Lottery, launched in 2011, runs five popular draws every week.
But the spokesman added: "In order to compete in today’s lottery market and to prevent charities from closing, it is essential that society lotteries are allowed to offer a significant jackpot in order to grow sales and thereby raise more money for good causes."
