David Cameron pledged in the Conservative party manifesto to hold a referendum on Britain's membership of the European Union “by the end of 2017”.
The language was deliberately loose to give the party flexibility – the most obvious reason was to allow it to negotiate deals with the Liberal Democrats or Ukip in the event of a hung Parliament but the other motives are now becoming clear since a majority Conservative government has made an EU referendum a certainty.
There are several motives for holding the referendum long before the end of 2017, with some insiders even suggesting it could be held as early as next year.
But would an early a referendum on the EU held next year winnable for the ‘in’ camp? Here are five reasons why the vote could be held in 2016 and why the ‘in’ camp should we worried.
1. Get it over and done with
With business leaders warning of two years of uncertainty as financial decisions are put on hold until after they discover the fate of Britain’s relationship with the EU, David Cameron and George Osborne may go for an early referendum in order to avoid harming their treasured economic recovery.
“The mood now is definitely to accelerate the process and give us the option of holding the referendum in 2016,” one insider told the Guardian. “We had always said that 2017 was a deadline rather than a fixed date.”
But an early referendum reduces the chances of Mr Cameron securing the more ambitious renegotiation he wants: EU-wide treaty change.
This will in turn reduce the chance of the British public voting in favour of a watered down 'renegotiated' settlement the Prime Minister manages to achieve because although polls point to Brits opting to stay in the EU, they also show strong opposition to the status quo in Europe. The thought of 'business as usual' in Europe will certainly not endear itself to a British electorate.
Failure to negotiate any meaningful reforms will only fuel the argument of anti-EU campaigners and anger the powerful euro-sceptic press in the UK.
2. German and French elections in 2017
European officials are worried a British referendum on the EU in 2017 would clash with the French presidential elections and the German federal elections taking place in the same year.
European officials were reluctant to enter any meaningful discussions on renegotiation before last week's UK election but after such a decisive outcome in favour of the pro-referendum Tories, government insiders expect European leaders to press ahead with the negotiations with the view to establishing an outcome well before the French elections in early 2017 and the German elections in September.
If negotiations are completed long before the French elections in the spring of 2017, there will be little point in Britain pro-longing the uncertainty and logic would point to holding a referendum at the end of 2016. This way the outcome would be settled before the elections across the channel and avoid the danger of affecting them.
3. Opposition to David Cameron's demands for treaty change
Mr Cameron has made it clear he wants any reforms he secures to be written into the EU treaty before he puts his renegotiation package to the British people.
This condition was absent from the Conservative party manifesto but again, this was to allow for flexibility and Downing Street has made it clear that the Prime Minister "wants treaty change".
However Wolfgang Schaube, the German finance minister, has dealt a blow to this key demand by saying a treaty change would be unlikely to happen soon.
What does five more years of the Tories mean for Britain?
What does five more years of the Tories mean for Britain?
1/8 Welfare payments will be slashed
One of the most controversial parts of the Conservative manifesto was to cut benefits for the working age poor by £12 bn over the next three years. But during the campaign they only said where £2 bn of these savings would come from. That leaves £10 bn still to find. Some experts think the only way they can close that gap is by means testing child benefit – with millions of families losing out
2/8 There will be tax cuts for those in work and those who die
The Tories will increase the threshold at which the 40p rate of tax becomes payable to £50,000 by 2020. They haven’t said so but it is also likely that at some point in the next five years they will abolish that 45p rate of tax altogether for the highest earners. They also want to increase the effective inheritance tax threshold for married couples and civil partners to £1m
3/8 There will be an in/out EU referendum in 2017
The next two years are going to be dominated by the prospect of a referendum on Britain’s membership of the EU. First off David Cameron has the daunting task of negotiating a deal with other EU leaders an acceptable deal that he can sell to his party so he can go into the referendum campaigning for a ‘yes’ vote. This may be unachievable and it is possible that the Tories may end up arguing to leave. Opinion polls show Britain is divided on EU membership, one poll this year showed 51% said they would opt to leave compared to 49% who would vote to stay in
4/8 There will be more privatisation of the NHS
Having won the election the Tories now have a mandate to go further and faster reforming the NHS. In order to make cost savings there is likely to be greater private involvement in running services, while some smaller hospitals may lose services they currently provide like A&E and maternity units
5/8 There will be many more free schools – and traditional state schools will become a thing of the past
The Tories plans to create 500 new free schools and make 3,000 state schools become academies. They will also carry on reforming the Department of Education and remove more powers from local authorities over how schools are run
6/8 On shore wind farms will be a thing of the past and fracking will be the future
Government spending on renewable energy is under real threat now the Lib Dems are no longer in power with the Tories. Subsidies are likely to be slashed for off-shore wind farm and other green energy supplies. Meanwhile there will be generous tax break for fracking as ministers try and incentivise the industry to drill for onshore oil and gas
7/8 There maybe more free childcare – but not necessarily
In the campaign the Tories pledged to double the amount of free early education for three- and four-year-olds from 15 hours a week to 30. The extra hours would only be offered to working families where parents are employed for at least eight hours a week. However they have not said where the money will come from to fund the pledge
8/8 Workers' rights could be reduced
The Tories want to slash business regulation, merge regulator and cut costs. The Lib Dems stopped them from reducing the employment rights of workers in power – but these are now under threat
He said: “The German government wants treaty change one day. We don’t think it will happen tomorrow. All we need to do to strengthen the economic and monetary union can be done without treaty change.”
If Mr Cameron fails to secure such a key demand in his renegotiation bid, it will undermine voters' trust in his or any other Prime Minister's ability to extract any meaningful change to an institution that the British public has very little confidence with in its current form.
Senior Euro-sceptic MPs have already indicated they are prepared to campaign to leave the 28-nation bloc in the 2017 referendum if he secures only cosmetic changes.
4. The referendum will be enshrined in law this year
Mr Cameron will include plans to legislate for an EU referendum in his Queen's Speech on 27 May.
With a Conservative majority in the House of Commons set to approve the bill when it is presented to MPs shortly afterwards, the Prime Minister will be given the power to call the referendum as and when he sees fit - paving the way for the first national vote on Britain's relationship with Europe in more than 40 years.
5. PM has re-appointed same Europe minister
Mr Cameron's decision to re-appoint David Liddington as Europe minister shows he is keen to continue the same approach to renegotiation - he opted against appointing a fresh face that would have signalled a return to square one.
Mr Liddington can resume the partnerships he has built up since being appointed to the post in 2010 and becomes the longest serving Europe minister in the process.