The European Union is in a “critical situation”, the German chancellor has said, as leaders meet in Slovakia to discuss ways to regain trust after the UK’s vote to leave the bloc.

Angela Merkel said they needed to show they could improve on security, defence co-operation and the economy. But EU countries are deeply divided over how to bolster growth and respond to the influx of migrants. Meeting in Bratislava without the UK, they will not discuss Brexit talks.

Meanwhile, the political future of Germany’s Vice Chancellor may hinge on the outcome of a vote next week by his Social Democrats (SPD) over whether to back a trade deal between the European Union and Canada.

SPD leader Sigmar Gabriel has championed the Comprehensive Economic Trade Agreement (CETA) as part of his remit as Economy Minister, and to demonstrate the centre-left party’s business credentials.

But critics on the SPD’s left wing are sceptical about the benefits of the deal and believe it would give multinationals greater access to European markets without creating jobs.

A failure to secure a majority of delegates at Monday’s SPD convention in favour of the accord could scupper Gabriel’s chances of standing as the party’s candidate for Chancellor in national elections next year. It might also unleash a damaging power struggle within the party, the junior partner in the coalition government led by Chancellor Angela Merkel’s conservatives.