Some charities feared they would go out of business if the Act, which was passed last week, had not gone through.
"Within five years, our operation would not have been financially viable," said Richard Simmonite, promotions commercial manager at St Giles Hospice in Lichfield, whose lottery accounted for a quarter of the money spent on care for people with cancer and serious illness last year.
Previous legislation had banned charities from selling tickets for more than £2, and from spending more than 35p out of every £1 raised on operating costs, rent and utilities.
The new Act includes no such restrictions, which means charities are free to increase ticket prices and spend more on costs, providing at least 20 per cent goes to good causes.
But charities that run lotteries have expressed concerns about new taxes included in the Act. Staff involved in the running of lotteries will be required to pay a licence fee, and the Government has reserved the right to charge a levy in support of its efforts to tackle problem gambling.
"We shouldn't be charged for problems we don't contribute to," said Garth Caswell, lottery manager at Ty Hafan Children's Hospice in Glamorgan. He also criticised the Government for not introducing a clause allowing the annual lottery fundraising limit of £10m to be reviewed regularly. "It is protecting the National Lottery," he said.
The Government has refused to ban children from using fruit machines, despite public support for a campaign led by the Salvation Army, NCH and the Methodist Church. The charities handed over a 50,000-signature petition to culture secretary Tessa Jowell earlier this month.