LONDON — The European Commission president vowed that Britain will not be able to renegotiate better terms to stay in the EU in case it votes in Thursday’s referendum to leave the bloc.

Commission President Jean-Claude Juncker said Wednesday that “out is out” in case of a vote to quit the 28-nation bloc.

There had been some reasoning that the EU would be so bent on keeping Britain in the EU that it would be willing to come up with new sweeteners to entice London.

British Prime Minister David Cameron obtained a series of concessions to limit immigration and commitments to stay out of closer union at a February summit of EU leaders before he called for the referendum.

Juncker said Wednesday that Cameron “got the maximum he could receive and we gave the maximum we could give so there will be no kind of renegotiation — not on the agreement we found in February nor as far as any kind of treaty negotiation. Out is out.”

NATO chief says EU with Britain key to trans-Atlantic security

The chief of the NATO alliance says Britain remaining in the European Union is key for trans-Atlantic security and common efforts to fight violent extremism.

NATO Secretary-General Jens Stoltenberg said Wednesday “it’s up to the people of Great Britain to decide whether to remain or leave.”

But he added, he can say what matters for NATO: “A strong U.K. in a strong Europe is good for the U.K., but it’s also good for NATO.”

Stoltenberg spoke to The Associated Press one day before British voters are to cast ballots in a referendum on EU membership.

He said that to face a daunting array of contemporary security threats, “we need a strong Europe and a strong NATO together.”

Stoltenberg added that “the UK is key in making sure that that happens.”

Hollande says UK exit would have ‘very serious consequences’

French President Francois Hollande says the European Union’s future is at stake in the British referendum Thursday.

The United Kingdom leaving the EU would have “very serious consequences,” Hollande said following a meeting with Slovak Prime Minister Robert Fico in Paris.

Hollande says he hopes the British will choose to remain in the EU.

Hollande says: “There’s a very serious risk for the United Kingdom not to be able to access the common market and … the European economic area anymore.”

France would “draw all the conclusions” of such a vote, he warned. “This would be irreversible.”

Norwegian PM says exit would leave Europe ‘fragmented’

Norwegian Prime Minister Erna Solberg fears a British vote to leave the EU would make Europe “weaker, more fragmented and nationalistic.”

In comments to Norwegian broadcaster NRK, the leader of the oil-rich Scandinavian country that has twice voted in referendums to stay out of the EU said a weaker Europe would mean the economic situation will be more difficult when reforms and competitiveness are needed.

“But it will also mean a more political and fragmented Europe, a weaker Europe and a weaker world,” she said in the interview on Wednesday.

She said that in a world where “we are increasingly dependent on each other and solve issues together, it’s dangerous to demolish joint institutions,” adding that she is “deeply worried” should Britain opt out of the EU.

Many of Germany’s big companies fear negative impact

A German economic think-tank says more than a third of industrial companies it surveyed in the country, Europe’s biggest economy, fear that a British exit from the European Union would have negative effects on their business.

The Ifo institute, which also produces a closely watched monthly business confidence index, said Wednesday that it surveyed 1,478 companies between June 6 and 21 to gauge their expectations of a possible British exit.

It said 38 percent of the firms questioned fear negative effects, and that those worries were particularly pronounced among companies with more than 500 employees. Another 61 percent expected no effect on their business, while just 1 percent expected positive effects.

Britain was the No. 3 destination for German exports last year and was Germany’s fifth-biggest trading partner overall.