Nick Clegg will today seek to upstage David Cameron at the World Economic Forum in Davos when he warns business and European leaders that the Tories are damaging Britain by "flirting with exit" from the EU.

The deputy prime minister will call for Britain to "stand tall in the EU" when he takes part in two events in Davos – a discussion on the new Europe with EU leaders, and a discussion about China – before Cameron takes to the stage.

Clegg has not attended the World Economic Forum for a few years. But he decided to put in an appearance this year amid fears that the prime minister is deterring investors from Britain by raising questions about Britain's EU membership.

A spokesperson for Clegg said: "Nick Clegg is … attending Davos to represent thousands of British businesses and the millions of British workers who rely on the UK's position in Europe. With European leaders discussing reform, he is not prepared to simply allow Conservatives flirting with the exit door to be the only British voice in this important debate.

"Nick Clegg has become so concerned about the damage being done to the reputation of UK Plc by the Tory party that he wants to take every possible opportunity to set out a more balanced view to investors and the international community."

In his first event of the day, Clegg, who arrived in Davos late last night, will join three EU prime ministers for a discussion about the new Europe. The group will include Fredrik Reinfeldt, the Swedish prime minister, who is Cameron's closest EU ally. But Reinfeldt leads the Moderate party, which remains in the European People's party group in the European Parliament after the Tories set up a new group with Poland's socially conservative main opposition party.

Tickets sold out within an hour for Clegg's second event, with the OECD general secretary Angel Gurría, which is entitled China, Europe and the US: the competitive challenge. Clegg will tell the event: "The UK cannot stand tall in the modern world if it doesn't stand tall in its own backyard. That means standing tall in the EU and working collectively towards growth.

"To trade successfully in the modern world, Britain must stay in. As an EU member, we have access to trade agreements with more than 50 countries around the world – and we've launched negotiations with the US.

"As power rises in the east and the US subsequently turns more of its attention in that direction, the importance to Britain of us being part of Europe will become even more apparent. It is vital for our country's prosperity and vital for British jobs. The commission has confirmed if the UK left the EU, we'd lose access to EU trade agreements with third parties and potentially have to negotiate them all from scratch, and negotiate from a much weaker position.

"We simply will not be taken seriously by the Americans or the Chinese if we're isolated and irrelevant amongst our own neighbours. We stand tall in Washington, Beijing, Delhi when we stand tall in Brussels, Paris and Berlin."

A Lib Dem source said: "This is not about raining or indeed snowing on the prime minister's parade. It is about making the case for Britain in Europe."