UK Prime Minister Boris Johnson has called for the country to “come together and get Brexit done” as Britons prepare to head to the polls for the first December election in almost a century. MPs backed holding a snap poll on December 12 – less than two weeks before the Christmas holiday – during a parliamentary vote on Tuesday evening. Mr Johnson hopes the election will return the Conservatives’ parliamentary majority and allow him to ratify his Brexit deal. The UK was due to leave the European Union on Thursday but this deadline has since been delayed, despite Mr Johnson’s “do or die” Halloween Brexit pledge. "It'll be a tough election and we are going to do the best we can," the prime minister told a group of backbench MPs. Main opposition party Labour has said it will get Brexit sorted by giving voters a second referendum with a choice between “a sensible Leave deal or Remain”. “A Labour government will be on your side, while Boris Johnson’s Conservatives – who think they’re born to rule – will only look after the privileged few,” Labour leader Jeremy Corbyn wrote in the Daily Mirror on Wednesday. Labour, traditionally the party of working-class voters, is pitching a radical socialist government, which would give more money to the National Health Service, nationalise some utilities while levying higher tax on the biggest earners. However, the two main political parties face a fierce challenge from the Liberal Democrats and the newly-formed Brexit Party. The Liberal Democrats have pledged to cancel Brexit which could win over Labour voters outraged at the party’s ambiguous stance on EU membership as well as Conservative supporters who backed Remain in the 2016 referendum. While the Brexit Party led by Nigel Farage could pick up working-class Labour Leave voters as well as Conservatives frustrated the UK has missed two Brexit deadlines. “At last the deadlock in parliament is broken, Brexit now has a chance to succeed,” Mr Farage wrote on Twitter after the snap poll was called. Polling this month showed the Conservatives were ahead of Labour by 10 percentage points. During the last snap election in 2017 polling in the beginning of the campaign predicted the Conservatives would keep their majority but in the end resulted in a hung parliament. Calling the election turned out to be a risk that failed for then Conservative prime minister Theresa May who was unable to get her Brexit deal passed through Parliament. The same fate befell Mr Johnson, whose attempts to push through his own divorce deal in a few days before the October 31 deadline were thwarted by MPs. A respected independent think-tank criticised the deal Mr Johnson agreed with Brussels on Wednesday, saying the economy would be 3.5 per cent smaller than if the UK stayed in the EU. The agreement would deliver a £70 billion blow over 10 years to the country, according to a study by the National Institute of Economic and Social Research. The study said a no-deal Brexit would be even more damaging, making the British economy 5.6 per cent smaller.