The fall-back position for the 18 October referendum is a streamlined committee system instead of the compromise option of cabinet and leader, raising the stakes for mayoral campaigners (LGC, 8 June).
The campaign was not due to start until early September, but the leaked document lifts the lid on efforts to establish one of Tony Blair's pet projects in the New Labour flagship council.
It acknowledges 'unease' about mayors in the Labour Party, and suggests tackling concerns about corruption and accountability head-on to gain its support.
Tories, Liberal Democrats and Greens should be 'challenged remorselessly' over whether they would field a mayoral candidate, despite opposing the policy.
No-campaigners were infuriated by statements such as 'let's attack the backward-looking Victoriana of the dinosaur committee-based alternative'.
Green group convenor and no-campaigner Keith Taylor warned the 'yes' campaign was funded by big business. If their candidate was elected, he or she would push Tony Blair's privatising plans, he said.
He added: 'There's nothing [in the document] about if Lord Bassam was mayor what he would do, he just talks about his megalomaniac ambitions to become one.'
He suggested the former Brighton & Hove leader, who was recently moved sideways to the whip's office from his junior minister-ial position in the Home Office, was seeking to use the position of directly elected mayor to regain more influence.
Lord Bassam, who was unavailable for comment, has not publicly declared plans to run for mayor. Chairman of the Yes for City Mayor campaign Roger French said: 'The mayor could be a business leader. There's also interest from communities who feel socially excluded from decisions.'