A new poll reveals that more than half of Britons now want to leave the European Union after the Paris attacks.
The survey of 2,000 showed that 52 percent of British voters wanted to leave while 48 percent wanted to stay.
This comes as in similar polls in June, July and September a majority of Britons had wanted to stay in the EU.
Last month, British Prime Minister David Cameron launched his attempt to reform the block ahead of a referendum on whether Britain should remain an EU member, a vote which he has promised will take place by the end of 2017.
Analysts say a British divorce would shake the bloc to its core, ripping away its second largest economy and one of its top two military powers.
Pro-Europeans warn an exit from the EU would hurt Britain's economy and could trigger the break-up of the UK by prompting another Scottish independence vote.
Other polls have shown British support for staying in the European Union fell this year as an influx of migrants into Europe raised concerns about membership.