Even to Kenny Dalglish and Liverpool FC, £500 million-plus is serious money.

Moreover, most of what little criticism there has been of the package came, significantly, only after the announcement of Greater Manchester’s deal, whose “earn back” tax provision – the first allowing local government to take directly a slice of national taxes – was rightly seen as genuinely ground-breaking.

Importantly, Manchester’s is not a deal with the city council, but with the Greater Manchester Combined Authority (GMCA) – the strategic authority for all ten Manchester boroughs, whose statutory city region status is clearly accepted by ministers as having at least the strength and accountability of a city mayor.

Under the deal the GMCA will invest £1.2 billion in infrastructure to promote economic growth, and – the headline bit – will be able to earn back and reinvest up to £30 million of the extra tax revenues generated from this growth.

The whole deal aims to create and protect more than 6,000 jobs, with other provisions including devolution of the Northern Rail franchise, 6,000 more apprenticeships, and up to 7,000 new homes.

Its potential impact on the local economy is huge, and, exceptional as the GMCA may be, this publicised deal constitutes a massive precedent, and, surely, a major addition to the Yes campaigners’ armoury.

Removal of mayors should also have been settled by now. In its impact assessment in January 2011, the Government asserted that, if mayors were going to exercise additional powers and freedoms, the accountability regime should include a recall mechanism – to be introduced “at a later date … alongside proposals for recall for other public officials”.

It would have been useful had ministers reminded voters of this pledge and given some vague hint of when the “later date” might arrive. Still, it remains Government policy, and the answer, therefore, to the question: “If we’re going to directly elect a mayor, how can we directly unelect a rubbish one?” is that, by the time the possibility arises, some recall mechanism should, as promised, be in place.

But what kind of mechanism? The Warwick Commission on Elected Mayors suggests that “an appropriate recall process”, enabling the removal of a mayor “in extremis”, might be one exercised through a vote of no confidence by the full council. That is not dissimilar to the Government’s current attempt to introduce a recall mechanism for MPs, controlled by other MPs, rather than by voters – a rapidly collapsing attempt, which probably explains why ministers are keeping so quiet about recall for mayors.

In this major extension of direct democracy, “an appropriate recall process” would seem logically to be one in which voters are the key players. A set percentage of a disgruntled electorate sign a petition, and thereby trigger a recall vote in which those same electors are asked if they want their mayor to be recalled, with a “yes” vote triggering in turn a by-election.

Finally, the “in extremis” issue. The Recall of Elected Representatives Bill – the one introduced, regrettably, not by the Government, but by Conservative MP, Zac Goldsmith – proposes that recall should kick into action not in extremis, but in any circumstances in which representatives lose the confidence of their electorate: if, say, they’ve acted financially dishonestly or disreputably, or broken promises made in an election address, or behaved in a way likely to bring their office into disrepute.

It might not be quite what ministers have in mind, but it could decisively boost the “yes” vote on May 3 and maybe even the turnout.

* Chris Game is from the Institute of Local Government Studies at the University of Birmingham