What Changes When the Prime Minister Does

Keir Starmer resigned this morning. Andy Burnham is now the overwhelming favourite to replace him and could be in office within weeks.

For those working in development, cost consultancy and investment, it is worth being clear about what that means commercially.

Burnham is not anti-development. His record in Greater Manchester is evidence enough: house prices rose 63% over the past decade against London's 7%, and major schemes like Victoria North and Mayfield were delivered on his watch. He knows that infrastructure and housing have to move together and has demonstrated he can bring private capital behind public ambitions.

But his instincts are more interventionist than anything the industry has seen from a Labour government in decades. And he inherits a delivery picture already under serious strain.

Starmer pledged 1.5 million homes this parliament. Between July 2024 and March 2026, around 342,000 were delivered, roughly 23% of the target. Planning consents fell 39% and housing starts dropped 31% in the three years to December 2025. Savills projects annual completions averaging around 167,500 through to 2030, well short of the 300,000 a year the target requires. Whoever takes the keys to No. 10 inherits that gap.

Three things about Burnham's likely approach warrant attention.

Planning decisions will carry more weight on social outcomes. Burnham has said so directly. Greater emphasis on social rent, affordable housing, transport connectivity and community benefit is not a speculation about his intentions. It is the model he ran in Greater Manchester and has said he will scale nationally. Developers pricing schemes against current planning assumptions may find those assumptions move. Viability assessments will face harder scrutiny. Cost and programme assumptions need to be stress-tested before entering the planning process, not after.

The land tax question is live. Burnham has backed proposals to replace Stamp Duty and Council Tax with a Land Value Tax. He called Stamp Duty a "tax on the aspirations of young people" as far back as his 2010 leadership bid. The policy detail is still being worked through and the fiscal reality of No. 10 may limit what actually happens. But any material change to the taxation of land alters the economics of acquisition and development appraisal. If you have live land deals or portfolio decisions in front of you this year, that exposure is worth understanding now. Attribution note: the Savills projection is a forecast; the 342,000 homes figure uses EPC-based estimates rather than finalised data and carries a margin of error.

The political cycle restarts. Seven Prime Ministers in ten years. Each transition brings a period where capital pauses, planning decisions slow and developers wait for policy clarity. That uncertainty has a cost. The schemes best placed to keep moving are the ones with robust cost and programme foundations already in place, where the commercial case does not rest on assumptions formed under a different policy environment.

Development does not stop, but the margin for poorly grounded decisions just got smaller.

If you are mid-scheme, reviewing a site or working through a portfolio decision, the political shift is a reason to have that conversation now rather than in September.