Andy Burnham is now the frontrunner to become Britain's seventh prime minister in a decade - and the mortgage market is already reacting
Keir Starmer announced his resignation as prime minister and Labour leader on Monday morning, confirming what the gilt market had been pricing in for weeks. Speaking outside 10 Downing Street, he said he had "heard the answer" of his parliamentary party on whether he remained best placed to lead it into the next general election, and accepted that answer "with good grace."
Andy Burnham - who won the Makerfield by-election last Thursday by more than 9,000 votes and stepped down as Greater Manchester mayor to return to Westminster - is the clear frontrunner to succeed him. A leadership contest opens on 9 July, with a new leader in place before parliament returns in September. Rachel Reeves is widely expected to leave the Treasury as part of the transition.
For mortgage brokers, the political story is also a market story - and it started moving before today's announcement.
Swap rates and fixed-rate pricing
The connection between political uncertainty and fixed-rate mortgage pricing runs through the gilt and swap markets. When Burnham's candidacy became serious in May, the 10-year gilt yield hit 5.137% - its highest level since 2008 - while 30-year gilt yields rose above 5.8%, a level last seen in 1998. Fixed-rate mortgage pricing is closely tied to swap rates, which in turn track long-dated gilt yields. That move was a preview of what a prolonged leadership transition could mean for rate sheets.
Burnham has pledged to maintain current fiscal rules, and yields settled back following his by-election win. The 10-year gilt stood at approximately 4.85% on Monday morning ahead of Starmer's statement. But with public borrowing already running above OBR forecasts, how durable that fiscal pledge proves once a new government faces the full cost of its programme will determine whether swap rates hold or push higher. Brokers should watch rate sheets closely this week and flag to clients approaching the end of fixed deals that the window for locking in may be time-sensitive.
Stamp duty, property tax and transaction volumes
The policy change with the most direct structural impact on broker business is Burnham's backing for proportional property tax reform. Under proposals supported by the Fairer Share campaign group, stamp duty and council tax would be abolished and replaced by an annual levy of 0.48% of the current assessed value of the property, with second homes, foreign owners and empty properties paying a higher rate of 0.96%.
The positive case for brokers is significant: abolishing stamp duty removes a transaction barrier that currently costs buyers thousands on completion and causes chains to collapse. A higher-volume transaction market benefits brokers whose origination depends on purchase activity. The flip side, as Knight Frank's head of UK residential research Tom Bill has noted, is that annual revaluations would turn house price growth into a recurring tax liability - a psychological shift that is likely to affect decision-making in higher-value markets, particularly in London and the south-east where the annual charge would be a proportionately larger share of household income.
The stamp duty angle also has an immediate practical implication. Clients who have been holding off on a purchase partly because of stamp duty costs may want to revisit their position - but brokers should caution that any reform requires legislation and a general election could intervene before it lands.
Buy-to-let: the Renters' Rights Act plus possible rent controls
Burnham has repeatedly called for lower rents and in 2023 wrote to the government specifically requesting powers to impose rent controls in Greater Manchester. Combined with the Renters' Rights Act, which came into force on 1 May 2026, this signals a more interventionist direction for the private rented sector than the current government has taken. Brokers with a significant buy-to-let book should be reviewing clients' existing products and stress-testing their positions against a tighter regulatory environment now.
The BTL market is not collapsing - but it is sorting. Landlords leaving tend to be the more leveraged, less professional operators. Those staying increasingly need active broker support as the compliance burden rises. That is a retention and cross-sell opportunity, not just a risk.
The immediate actions
For most mortgage brokers, three things are worth doing today. Clients with fixed-rate deals expiring in the next six months should be contacted to assess whether to lock in now given uncertainty around swap rate direction. Landlord clients should be briefed on the combined impact of existing legislation and the likely direction of travel under a Burnham government. And clients in higher-value markets who have been sitting on purchase decisions should be given a clear-eyed view of what stamp duty abolition could mean - and when.
The leadership contest runs until September. The uncertainty does not wait that long.
For full analysis of the Burnham policy agenda and the mortgage market: Andy Burnham is heading for No 10. Here is what that means for your clients' mortgages.
Want to be regularly updated with mortgage news and features? Get exclusive interviews, breaking news, and industry events in your inbox – subscribe to our FREE daily newsletter. You can also follow us on Facebook, X (formerly Twitter), and LinkedIn.
