BBC News Online gets to the bottom of a bitter and very public row.

Why are shareholders so desperate to get rid of Michael Green?

They have never really forgiven him for the ITV Digital debacle, but were unable to strike until the merger had been cleared by the competition authorities.

The digital terrestrial service was an ambitious and costly attempt to beat satellite broadcaster BSkyB at its own game.

But a series of strategic blunders - such as massively overpaying for Nationwide league football rights - and technical problems led to its collapse in 2002.

The whole adventure cost Carlton and Granada shareholders �1.2bn.

But wasn't Granada boss Charles Allen also to blame for ITV Digital?

The Granada chairman must take his share of the blame, and at one point investors were reportedly calling for his head too.

But Mr Green is, ultimately, an easier target for shareholders, as a good case can be made for ousting him on corporate governance grounds.

He was planning to step up from chief executive to chairman - a move increasingly frowned upon by the City, which prefers chairmen to be brought in from outside.

Mr Green has also led Carlton through one of the longest advertising slumps in memory, which some have blamed on the quality of its programmes.

And there is also concern that he will find it hard to work with Mr Allen, who is to become ITV's chief executive.

The pair have never got on particularly well, and their working relationship has been compared to "two ferrets fighting in a sack".

How distressing will all this be for Mr Green personally?

It is hard to overstate how much of a personal blow it will be for Mr Green, to be ousted from the new ITV set-up.

Carlton Communications is very much his baby. He single-handedly built it up from a small video production company into the second largest ITV franchise.

And he has been a key architect of the merger with Granada.

He recently said he wanted to be at the helm of ITV until he was 80 - remarks greeted with alarm by shareholders.

What will it mean for the future of ITV?

The Carlton board argued that to fire Mr Green now risked de-railing the merger.

They said negotiating his skills were needed in discussions with the Office of Fair Trading, otherwise "key benefits of the merger" will be lost.

But this was dismissed by Carlton's most powerful shareholders and the Granada board, making Mr Green's position untenable.

In the long term, his departure could make a US takeover of ITV - which is likely to be on the cards following the relaxation of media ownership rules later this year - more likely.

A chairman brought in from outside the existing ITV set-up might be less inclined for fight for its independence.

I thought this sort of stuff normally went on behind closed doors - how come it has developed into such a public row?

City institutions have always worked behind the scenes to impose changes on company boards.

What is different here is that shareholders have gone public with their objections.

Their aggressive approach left the Carlton board with very little room for manoeuvre.

It is a reflection of a new mood in the City, where falling markets and a harsher economic climate have made fund managers less tolerant of perceived boardroom incompetence.

The ITV shareholder revolt is also being seen by some commentators as vindication of the Higgs Report into corporate governance.

Higgs called for shareholders to call company bosses to account.

Other companies to feel the wrath of institutional shareholders in recent months include GlaxoSmithKline, where executive pay was the issue, and BSkyB, where plans to install chairman Rupert Murdoch's son James as chief executive have met with opposition.

Barclays shareholders have also led calls for it to justify its decision to move chief executive Matt Barrett to the position of chairman, following his recent remarks on credit cards.

What does it all mean for viewers?

In the short term, not a great deal.

The ITV merger has been sold as a boon to viewers, with the cash saved on economies of scale being ploughed back into programme making.

Of the two merger partners, Granada, which makes Coronation Street, has the stronger programme-making heritage.

Michael Green's Carlton has often taken the blame for "dumbing down" ITV's output.

But the new company will be under pressure to chase ratings from the outset.

It is unlikely to usher in a new golden age of public service broadcasting.