A minister stressed that a wave of policies being announced by Andy Burnham will be funded from existing Whitehall budgets rather than tax rises.
Science and innovation minister Chris McDonald insisted that the Government was re-prioritising schemes as it announced speeded-up moves to crack down on dodgy discounts and “subscription traps”.
He made the fiscal commitment as Mr Burnham was embarking on a cost-of-living tour on Monday pledging to provide “everyday fixes” for rising bills.
But the new Prime Minister faced growing questions over whether he is planning to bring in a new wealth tax in the autumn Budget to pay for more far-reaching measures to tackle the cost-of-living crisis and rebalance Britain’s economy.
Mr Burnham is struggling to persuade former Treasury minister and ex-Goldman Sachs economist Lord O’Neill of Gatley to join his Government, according to The Times.
The peer is said to have concerns about potential wealth taxes and to also want to continue his business interests.
Mr McDonald, on the media round for the Government, was repeatedly asked to rule out wealth taxes such as higher capital gains tax.
He declined to do so, stressing that such matters were for the Budget.
“But in the period that we're in now, the policies that are being announced are costed within departmental budgets,” he told Times Radio.
Mr Burnham has previously backed a new property tax, to replace council tax and stamp duty, which would hit London with an extra £7.5 billion bill.
He has played down the prospect of such major reform happening imminently.
"It's just not the case that we are bringing forward plans, on that scale, at this moment in time,” he said.
But this stopped far short of ruling out significant changes to property tax in the autumn Budget or later years.
The Prime Minister has also signalled that he may increase taxes on the better off to fund more public spending or tax cuts for the less well off, possibly by raising the £12,570 threshold at which people start paying income tax.
Mr Burnham intends to spend much of the rest of August travelling the country asking the public how the Government can improve their lives, according to No10.
He was due to announce a series of “everyday fixes” to reduce costs, promising to “pull every single lever we can to provide people with some room to breathe on the cost of living”.
He is accelerating plans to tackle “subscription traps” by requiring companies to make it easier to cancel subscriptions and provide more information about costs up-front rather than quietly auto-renewing them at a higher price.
The changes, announced in April, had been expected to come into force next spring, but Mr Burnham will bring their introduction forward to January.
He will also launch a consultation on adding deceptive discount offers to the Competition and Markets Authority’s list of banned practices.
This would make it easier for the watchdog to punish firms that engage in practices such as artificially inflating prices and then immediately offering a “discount” to make a product look much better value than it is.
The Prime Minister said: “I know people are sick and tired of rip-off discounts and subscription traps.
“Westminster has got used to telling people that everyday hassles like this are just part of life.
“I don’t think that’s right, especially when the cost of living continues to weigh heavily on so many people’s lives.”
Dame Clare Moriarty, chief executive of Citizens Advice, welcomed the proposals, saying subscription traps and deceptive discounts were “a widespread problem”.
Citizens Advice has previously found 26% of UK adults had accidentally taken out a subscription in a single year, with the Government saying its action on subscriptions could save households £14 per month.
Further announcements are expected over the summer, with the Prime Minister describing Monday’s proposals as “just the start”.
But Opposition figures have criticised his August plans as a “vanity tour” offering only “tinkering”, and urged him to implement broader tax cuts.
Mr Burnham’s summer tour follows his pledge on his first day in office to give the public “breathing space” on bills.
In his first week in Downing Street, he announced cuts to VAT on household electricity bills, a £2 cap on bus fares outside London and vowed to end rough sleeping.
But it quickly emerged that funding had not been fully nailed down for at least some of the schemes.
