Business Secretary Sajid Javid has insisted that he is still a Eurosceptic "Brussels basher" despite throwing his support behind a Remain vote at the EU referendum.

The top Tory revealed to the British Chambers of Commerce's annual conference in London that his decision over the 23 June ballot was a struggle between his head and his heart – his head ultimately winning the battle.

Javid, who is tipped as a future Conservative leadership contender, also told the Westminster audience that the uncertainty of a Brexit – "the enemy of jobs and growth" – could be damaging to business.

But the business secretary also stressed that the UK must look beyond trade just with its neighbours whatever the result of the EU referendum. "I have no time for ever closer union," he added.

Javid spoke ahead of Labour leader Jeremy Corbyn's address to the BCC conference. The cabinet minister suggested that the left-winger's politics had not change over the past four decades.

John Longworth, director general of the BCC, addressed the conference after the business secretary.

"The people of our country now face a choice, between staying in what is essentially an unreformed EU, with the Eurozone moving off in another direction and with Britain sitting on the margins, or leaving the EU, with all the near-term uncertainty and disruption that this will cause," he said.

Longworth added: "Undoubtedly a tough choice. You might say, a choice between the devil and the deep blue sea. Business leaders are, of course, by and large driven by economically rational decision making.

"Decision making in business suffers from the pressures of the short term and is naturally focused on the interests of the particular business concerned."

The latest online opinion poll from ICM, of more than 2,000 people between 26 and 29 February, put Leave and Remain neck-and-neck on 41%, with 18% of respondents undecided.