The European Commission President Jean-Claude Juncker will urge EU leaders at a summit next month to back free trade talks with the United States in the face of growing scepticism in member states.

The Commission, which negotiates on behalf of the 28 EU members, and US President Barack Obama’s administration want to conclude talks by the end of this year, but public debate is dominated in Europe by vocal opposition from anti-globalisation, ecological and consumer groups.

Juncker, who has set a balanced trade deal with the US as a priority, is said to be exasperated that some of the EU leaders who approved the initial negotiating mandate in 2013 have become increasingly critical of the talks on the Transatlantic Trade and Investment Partnership (TTIP).

“If we are to deliver on this commitment, we have to make sure that we are all rowing in the same direction,” a spokesman told a news conference.

He said Juncker felt EU leaders needed now to establish what they wanted from the TTIP talks and would ask them at the summit on June 28-29 to reconfirm the Commission’s mandate. It is not the first time that Juncker has sought backing for the talks. German Vice Chancellor Sigmar Gabriel criticised Chancellor Angela Merkel in a newspaper interview published on Sunday for saying that a trade deal was possible this year and questioned whether it was worth continuing negotiations with Washington.

French President Francois Hollande said last week there could be no agreement unless all the EU’s requirements were met, while urging Washington to offer more.

The Commission spokesman said talks were advancing and entering a crucial phase. The two parties are aiming to have a text agreeing on as many issues as possible by the end of July, with the most difficult points left to the final months of 2016.

A sense of urgency to clinch an accord before Obama leaves office in January is building on both sides of the Atlantic amid concerns that his successor may not be as committed to free trade deals.

An opinion poll published last month showed plunging public support for the TTIP in both Germany, the EU’s largest economy, and the US.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.