David Cameron and Nick Clegg's long-planned coalition reboot was hit by their vulnerability to omnishambles today, when the government's leader in the House of Lords announced his resignation with immediate effect.
Lord Strathclyde will be replaced by Lord Hill, a peer who tried to resign last year but was disappointed to discover the prime minister had not even noticed.
"While I have the highest respect for the privilege and duty of public service I do not see a political career as the cap to everything and would like, while there is time, to take up other threads of my life and other interests," Lord Strathclyde wrote to Cameron.
"We are now closer to the next general election than the last and you need an energetic team around you who can support and inspire you to victory and a new conservative government."
The two men discussed his departure over the new year, when Cameron unsuccessfully tried to convince him to stay.
The prime minister praised his political career – which has seen him operate on the Tory frontbench for a quarter of a century – during Cabinet this morning.
While friends insisted there was no political dimension to the resignation, Lord Strathclyde probably left because the death of House of Lords reform left him with little to do.
The resignation will serve as an unfortunate prelude to Cameron and Clegg's coalition reboot today, in which they will highlight the policy areas where they can still function cooperatively.
"Is it not a tad careless to lose a member of the Cabinet on the day you relaunch your government?" shadow immigration minister Chris Bryant tweeted.
Shadow business secretary Chuka Umunna tweeted: "You replace a Cabinet minister with one who tried to quit and then announce it on the day of your relaunch - the incompetence is staggering."
Analysts questioned why Downing Street had failed to tell lobby journalists about the story, thereby increasing the chanes of it being reported negatively.
There were also questions about why the news was announced today - just hours before the coalition reboot press conference - when it could have been more quietly released on Friday afternoon or Sunday.
The selection of Lord Hill as his replacement is potentially just as embarrasing as the resignation. His failed attempt to quit last year - which saw Cameron ignore him and then mutter that he should carry on his good work - is now part of Westminster folklore.
He had tried to resign due to contradictory signals from Downing Street, but Lord Hill will now face some of the toughest areas of coalition in-fighting in the Lords, where cooperation between Lib Dems and Tories is threatening to break down altogether.