Charlie Jeffery, senior vice-principal of the University of Edinburgh, is a professor of politics and a specialist in constitutional change. He has advised the British government and parliament, led research on the future of the UK and played a leading role in the debate about Scotland's independence referendum.

Many students at the University of Edinburgh come from Hong Kong and the mainland. Jeffery was here to further ties and to deliver a speech at the Foreign Correspondents Club on the implications of the referendum.

People watching from Hong Kong may be forgiven for thinking that when Scotland voted "no" to independence that would be the end of the matter. But Jeffery points to a "chain reaction" caused by the independence vote, which could yet bring a constitutional shake-up to the UK.

"I have been using this chain-reaction metaphor from the physical world, and I think the idea suggests there can be all sorts of different paths set loose by that reaction, and we are not sure which one will be the dominant one. There are all sorts of uncertainties," he said.

Those events began with an opinion poll shortly before the referendum that suggested a shock vote in favour of Scottish independence might be on the way. That had leaders of the UK's leading political parties scrambling to woo "no" votes by offering further powers to Scotland's parliament if the country chose to stay part of Britain.

Jeffery said the outcome of the vote - 55 per cent against independence and 45 per cent for - was not a surprise: "I think the odds were always for a 'no' victory. If you take that literally, the bookies were always clear this would be a 'no' victory. In the end it was possibly a bit more definitive than expected."

But what did surprise him was the reaction of Britain's prime minister, David Cameron. The day after the vote, Cameron announced that while the pledge to devolve more powers from Westminster to Scotland would be honoured, that must be in tandem with furthering the interests of other parts of the UK. "We have heard the voice of Scotland - and now the millions of voices of England must also be heard," he said.

"A lot of people went to bed thinking it was all about Scotland and woke up hearing the prime minister talking about England. So constitutional reform for England is now on the agenda sparked by what happened in Scotland."

Scotland, Wales and Northern Ireland all have their own legislatures with certain powers devolved to them from Westminster. The same is not true of England. This has led to calls from people in England for more of a say.

"It is clear people in England are unsatisfied with the current arrangements. They think the political system does not give them a voice in the way it does to Scotland, Wales and Northern Ireland through the devolved institutions. So there is a popular concern that Cameron was responding to," said Jeffery.

Cameron proposed allowing only English MPs to vote on English matters in Westminster.

"That is not really a solution to the problem because it only gets at the end of the process in forming legislation. We need earlier stages in the process to make the whole thing work. That means a capacity to think about England as a political unit," said Jeffery.

"Constitutional reform in England is really challenging," he added. This is partly because of England's greater size but also because the government of England is so bound up with the government of the UK as a whole. "It is quite difficult to disentangle England from the rest in order to produce an institutional form which will sensibly collect and represent and pursue the interests of people in England."

Another surprise has been a dramatic surge in membership for the Scottish National Party, prime movers in the push for independence, since the referendum. It is now the third biggest party in the UK.

These events are reshaping British politics. The opposition Labour party, which campaigned for a "no" vote in the referendum, looks as if it might now lose Scottish seats in Westminster in next year's general election.

Meanwhile, Cameron's move to support greater influence for England is probably driven by short-term political objectives, says Jeffery. The prime minister's Conservative Party is facing strong opposition from the UK Independence Party, described by Jeffery as "something like England's nationalist party".

The need to combat UKIP, which takes a strong line on immigration, has also led Cameron to talk tough on the UK's membership of the European Union. He has promised another referendum, this time to decide whether Britain should stay in the EU, by 2017, raising fresh challenges. Support for membership of the EU is much stronger in Scotland than in England.

Constitutional change in the UK is taking place in an unpredictable way, with one development prompting another. "That's the way it has always been done in the UK," said Jeffery. "No one has ever taken big picture thinking."

He added: "That leaves us in a position which is largely disintegrative. You adapt to whatever the situation is for one part of the UK, and it has a spillover effect somewhere else. You adapt to that, onward and onward, and there is nothing in the centre holding it all together. I think the trajectory is for the UK to become ever looser in the union it provides for its component parts."

While the way these events will develop is uncertain, Jeffery says there are positives that can be taken away from the process by which the decision on Scottish independence was made.

The British government, which does not support Scottish independence, gambled on a referendum - and the gamble paid off. Jeffery said the decision to allow the vote was intended to ensure support for independence did not strengthen. "That demand was allowed to be expressed and those expressions opposed. It produced an outcome which is that Scotland is not independent."

Jeffery said: "I am not sure what the read-across for Hong Kong from all that is. But it does suggest if there is openness to the expression of the popular will, it will not bring the world crashing down."

The professor said the Occupy protests would have been cleared by police had they occurred in the UK. "Imagine occupy protesters in London had blocked roads around the House of Commons. I think protesters would have been moved with, necessarily, an element of force. I think it is quite remarkable that the authorities [in Hong Kong] have not used that kind of force."

He added: "There is probably a little bit of an element of double standards from countries from outside Hong Kong if you imagine such scenes [elsewhere]. Police would have moved in and moved them out. That has not happened here. That is probably quite a good thing."

Electoral democracy does not necessarily appeal to everyone living under such a system, said Jeffery. But he does not believe the business sector loses influence under a democratic system, as has been suggested by some commentators in Hong Kong and the mainland.

"I don't see that business is un-influential in the UK. The influence happens in a different way. That's why all the major political parties get financed significantly by businesses because they are effectively lobbying for their voice to be heard. That's also part of democracy.

"There are plenty of other places in the world which have great economic dynamism amid democracy and don't suffer for it. You will probably find business interests are powerful in the way in which they interact with political parties."

In the Scottish referendum, big business was mostly against independence and made its position clear. This had a significant impact on public opinion, said Jeffery.

The professor said he knew very little about the details of the situation in Hong Kong and was not in a position to give advice. But he believes it is important that whatever process is adopted for constitutional reform must be seen as a legitimate one.

"The Scottish referendum was a great example of that. The two sides said 'we will abide by the result whatever it is'. That was really important. But then the level of civic engagement was very high, including much that wasn't organised by the campaigns or the political parties. It was self-organised both in terms of formal meetings in village halls and so on, but also in conversations on the bus. People were in everyday settings talking about Scotland's constitutional future."

That was reflected in the fact that 97 per cent of eligible voters registered for the referendum and 85 per cent voted. "I think it is impressive, and it gives the outcome legitimacy. Other situations have to find their own way to legitimacy. Whatever happens [in Hong Kong], has got to happen in a way which ultimately brings the consent of people on different sides of the argument."