The FTSE 100 lost its fizz to trade flat as Andy Burnham delivered his first conference speech as prime minister.
Gilts, the UK government's bonds, avoided a fresh sell-off after Burnham paired plans for more public ownership with a pledge to stick to the fiscal rules.
The backdrop remains fraught, with the Debt Management Office selling £4.25 billion of 10-year gilts earlier at an average yield of 5.38%, the highest since September 1999.
Burnham told the Labour Party conference in Liverpool that the state pension triple lock would be replaced by a cheaper double lock from April 2030 to help fund a National Care Service.
The triple lock raises the state pension each year by the highest of inflation, earnings growth or 2.5%.
On water, he said the government would bring a bill to Parliament to repeal the ban on public ownership of water companies.
Mayors will also get new powers to hold water firms to account, including blocking "excessive bonuses" for bosses.
He announced a publicly owned company, the Great British Grid, to speed up connections to the electricity network by increasing competition for connection projects.
Councils will be given powers to take over empty homes and bring them back into public housing stock.
Burnham stressed partnership with private companies, which helped calm fears of a costly nationalisation drive.
Investors will now look to the budget on 28 October for proof that his spending plans fit the fiscal rules.
