It’s been a brutal few weeks for public markets M&A in Europe. BHP’s [ASX:BHP] GBP 38.6bn (USD 49bn) equity value pursuit of Anglo American [LON:AAL] and a possible offer for Naturgy [BME:NTGY], worth EUR 24bn (USD 26bn) before talks broke down, both ended without agreement.

There’s also market concern another big transaction failure could follow, with DS Smith’s [LON:SMDS] shares trading at a 30% spread to an all-share offer from International Paper [NYSE:IP] that is currently worth GBP 6.3bn. This is one of the widest deal spreads in Europe.

It remains to be seen whether trouble among some of the region’s largest deals simply reflects idiosyncrasies around individual transactions or demonstrates a more fundamental shift in M&A sentiment across the region.

Anglo American’s size and corporate structure, including Johannesburg-listed subsidiaries Anglo American Platinum [JSE:AMS] and Kumba Iron Ore [JSE:KIO], proved too large and complex for BHP to unpick.

Meanwhile, Abu Dhabi-based energy utility TAQA withdrew its interest in Naturgy after discussions about a joint bid with major shareholder CriteriaCaixa ended without an agreement last week.

For DS Smith the stakes are even higher. Investors are fretting that an already agreed deal with packaging peer International Paper could be on the rocks. Brazil-based peer Suzano [BVMF:SUZB3] now reportedly wants to acquire International Paper in a transaction that it has been claimed would be conditional upon termination of the DS Smith tie-up.

Shares in DS Smith declined almost 6% last week, widening the spread to International Paper’s all-share offer by six percentage points to 30%.

Europe’s failed deals threaten to upend a strong start to the year for M&A, which featured a host of early-stage bids for large, listed companies. They also come at a time when capital markets have been roiled by political upheaval at home and abroad.

In South Africa, where many of Anglo American’s key assets are located, BHP’s bid for the UK-listed mining company became politically controversial during elections in the country.

In Europe, a surge in votes for far-right parties to the European Parliament sparked a snap election in France and broader financial uncertainty. There are further wild cards in the year ahead with UK and US elections on the horizon.

The VSTOXX index, a measure of month-ahead volatility in European equities, jumped seven points last week to 21 points at the end of Friday trading. That’s the highest since April when rising tensions between Israel and Iran soured investor sentiment.

And there are a host of other large deals in Europe that remain delicately balanced midway through the year.

BBVA [BME:BBVA] is attempting a hostile, EUR 11.5bn equity value bid for domestic banking peer Banco de Sabadell [BME:SAB] with the target’s stock price trading at a 7% spread to the implied value of the all-share offer. Paris-based renewable energy generator Neoen [EPA:NEON] is in talks about a potential EUR 39.85 per share bid worth EUR 6.2bn from financial sponsor Brookfield. Its stock price closed on Friday at EUR 36.40, a 9% spread.

And a consortium including CVC, Nordic Capital and Abu Dhabi Investment Authority are mulling an offer for Hargreaves Lansdown [LON:HL.], which could lead to a take-private of the GBP 5.1bn market cap stockbroker. Shares in Hargreaves Lansdown closed last week at GBP 10.51, 7% above the GBP 9.85 per share bid its board previously turned down.

Lapsed deals involving Anglo American and Naturgy mean dealmaking sentiment has taken a knock in recent weeks. All eyes will now be on DS Smith, Sabadell, Neoen and Hargreaves Lansdown to see if the lapsed deal spike over the past few weeks was a one-off or part of a broader trend.