European Central Bank officials are growing increasingly worried that Donald Trump’s victory in the US presidential race may harm the eurozone by hurting trade with the US and fuelling populism.

Speaking publicly and behind the scenes, ECB officials emphasise any US shift towards protectionism under Trump could hurt the already fragile eurozone economy and pave the way for an even stronger backlash against globalisation and the euro project.

This could hinder the ECB’s efforts to revive growth and inflation in the eurozone just as the economic picture was starting to look less bleak.

If they only looked at financial markets, ECB rate setters should be moderately pleased: eurozone inflation expectations, bond yields and stocks have all gone up since Trump’s victory, showing investors are betting on spending-led stronger US economic growth.

In addition, higher bond yields have eased immediate concerns the ECB may run out of German debt to buy in its €1.74 trillion asset-purchase programme, the centre-piece of its stimulus strategy.

However, top officials stress the situation is far more complex than this and the ECB still looks still set to announce an extension of its bond- buying beyond their March deadline at the bank’s December 8 meeting. First, rising borrowing costs for indebted peripheral governments show that investors are pricing in rising political risk in the eurozone as anti-globalisation and eurosceptic voices are emboldened by Trump’s win, which came hard on the heels of the Brexit vote.

This was particularly visible in Italy where the government’s borrowing costs were on track yesterday for their biggest two-week rise since the 2012 debt crisis and banking stocks fell ahead of a December 4 referendum that could unseat pro-euro Prime Minister Matteo Renzi.

“The overall [market] signal is not clear cut,” a central bank official said, stressing it was still too early to consider any countermove.

Second, vice president Vitor Constancio has warned that any fiscal easing in the US – such as Trump’s planned infrastructure spending – may not benefit the eurozone if the new US administration sticks to its ‘America first’ pledge, hurting Europe’s exports to its biggest trading partner.

Even a hawkish member of the ECB’s executive board, Yves Mersch, warned that growth in the eurozone was still “fragile” and the inflation pick-up not yet sustainable.

This was further emphasised by president Mario Draghi, who said yesterday the recovery relied on continued monetary support from the ECB.

Both Mersch and Draghi also warned that rolling back financial regulation could pave the way for a repeat of the 2008 crisis.