Mr. David Cameron is facing the biggest challenge of his career.  After reaching an agreement with Brussels, the in/out referendum expected this June will define British Prime Minister’s legacy.

Britain will be voting in another major referendum, nearly two years after they voted on Scotland’s future as part of Great Britain. This time, their vote will essentially decide if Britain should remain a part of the European Union or leave the bloc. Should the latter prevail, it will be the first time in EU history that a member country will have left the bloc.

Cameron announced a draft deal on his renegotiation of Britain membership in the EU. Indeed, after two-days talks at the European Council, in order to find a shared position, the proposed agreement seems to satisfy most of the Prime Minister’s demands mentioned in his letter of 10 November 2015.

Among the key demands, the deal looked promising for Britain on assurances that non-eurozone countries would not been discriminated, exemption from the European Union goal of an “ever close Union” and cutting back on European Union regulation. Nonetheless, restricting welfare benefits to european migrants seems to be precarious.

The deal includes an “emergency brake” on in-work benefits for EU migrants for up to four years, when there is an exceptional influx. Britain could restrict benefits for workers, but the brake will be relaxed over time. Thus, Eastern European countries, who had wrangled over the welfare demands, were only partially successful in restricting cuts to new arrivals rather than European migrant workers already in the UK.

But, after securing the support of European leaders for the reform package, now it is time for Mr Cameron to sell it to a skeptic public, who always played down the EU benefits. The next few months are expected to see intense campaigning for the respective positions before the British public eventually vote on the question, “Should the UK remain a member of the EU or leave the EU?”