Should the UK remain in the EU? 40 years ago today Britain said yes. What are the chances of us giving the same answer?

A 'Yes' vote rests on David Cameron's ability to secure wide-ranging reforms

Plans for an in/out referendum on EU membership received a boost as Labour dropped its opposition to the vote (AFP/Getty Images)

On this day in 1975 the British public were voting in the first national referendum: Should the UK remain part of the European Community?

Fast-forward 40 years and Britain is still trying to answer the same fundamental question, albeit the European Union and not the EC.

A bill is currently going through Parliament to enshrine into law Mr Cameron's pledge to hold a referendum on the UK's membership of the EU before the end of 2017 and the vote could be held as early as next May.

But will today's British electorate vote in the same way as it did in 1975? Much will rest on the Prime Minister's efforts to renegotiate the UK's relationship with the 28-state bloc

Below are seven key areas where the Prime Minister will have to secure reforms if he is to persuade an increasingly eurosceptic public to replicate the outcome of 40 years ago and stop the UK from becoming the first nation to exit the EU.

1. Benefit tourism

The toughest challenge of Mr Cameron's efforts to secure meaningful reforms to Britain's relationship with the EU is his call to restrict EU migrants' access to Britain's welfare system.

The free movement of people is a fundamental principle of the EU but it has led to soaring levels of immigration to the UK as a relatively strong economy has attracted workers from struggling European economies - a phenomena that the UK government has no control over.

Mr Cameron, instead of choosing the impossible path of trying to crack down on one of the founding principles of the EU - freedom of movement - has opted for the more realistic move to tackle EU migration by limiting the appeal of Britain's welfare system to foreigners.

German Chancellor Angela Merkel will be a key figure in determining whether Britain stays in the EU. (Rex Features)

He wants to do this by blocking EU migrants' access to tax credits and child benefit until they have lived and contributed to tax revenues for four years; restrict their access to council housing; ban EU migrants from sending child benefit or child tax credit abroad, block EU migrants from claiming jobseekers' allowance and deport any EU migrants who have not found a job within six months of arriving in the UK.

Mr Cameron has insisted that these changes to welfare to cut EU migration "will be an absolute requirement in my renegotiation" and wants the reforms to be enshrined in new treaties.

German Chancellor Angela Merkel, French President Francois Hollande and other major EU leaders are resistant to treaty change however, and Eastern European states are set-against Mr Cameron's bid to block access to the welfare state. European leaders argue his proposals would contravene the principle of freedom of movement.

David Cameron invited European Commission President Jean-Claude Juncker to Chequers in a bid to kick-start his renegotiation bid

2. Repatriating powers to national parliaments

Mr Cameron wants national parliaments to be given the power to block EU legislation, thereby restoring the UK Parliament's sovereigntly and giving MPs the power to say no to "unwanted" European laws. This is a move welcomed by a host of fellow European leaders but Ms Merkel will be more resistant as it will represent a significant step-back to European integration.

3. An opt-out of 'ever closer union'

Mr Cameron wants Britain to be exempt from one of the key principles of the EU - the goal of moving towards an "ever closer union".

The principle was laid out in the 1958 Treaty of Rome - before the UK joined the European project - and Mr Cameron is likely to face opposition from countries such as France, who will point out that the wording refers to an "ever closer union among the peoples of Europe" and not the 'states of Europe'.

4. Cut back red tape

Mr Cameron wants to free businesses up from the "excessive interference" of the EU's bureaucratic rules and regulations that he claims holds back enterprise and efficiency. He will have no trouble convincing Ms Merkel in this area of reform and it is one of Mr Cameron's demands that stands a high chance of succeeding.

5. Strengthening the single market

In tandem with cutting back on red tape, Mr Cameron wants to break down trade barriers by opening up new markets for EU businesses.

He is calling for EU leaders to "turbo charge" free trade deals with mass markets in America and Asia, as the current free trade negotiations with the United States and South Korea are attempting to achieve.

This is a move welcomed by the powerful Western states in the union and is likely to be welcomed by the EU as a whole.

Former Conservative chancellor Lord Lawson believes David Cameron's efforts to secure reforms to the EU will be 'of no significance at all'

6. Protection against changes to the Eurozone

Mr Cameron will push for safeguards to protect Britain against the further integration of the Eurozone. He wants to ensure the currency bloc does not undermine the integrity of the Single Market, which may disadvantage the UK.

This could prove troublesome with Ms Merkel, who is keen to push ahead with wide-ranging reforms to the Eurozone without enacting treaty change.

7. Financial protection for the City of London

The Conservative party manifesto promises to safeguard Britain "as a global centre of excellence in finance" and will do so by resisting attempts by the EU to restrict "legitimate financial services activities".

This move may prove tricky as the powerful Ms Merkel and Mr Cameron have not exactly seen eye-to-eye with previous EU plans to move towards a fiscal union, that the Prime Minister warned would hit Britain's financial sector.

The German Chancellor has to balance UK calls for less regulation with demands to reform the Eurozone, which requires more fiscal rules.

@matt_dathan