SALZBURG, Austria, Sept. 20 (Xinhua) -- European Council President Donald Tusk said Thursday that Britain's Brexit proposals "will not work" as it may risk undermining the EU single market.
Tusk made the statement at a press conference following a two-day informal summit partly focusing on Brexit talks in the Austrian city of Salzburg.
Regarding British Prime Minister Theresa May's Chequers plan for Brexit, Tusk said that "the suggested framework for economic cooperation will not work, not least because it risks undermining the single market".
May defended her Chequers proposal for Brexit on Wednesday when arriving in Salzburg by saying that "It's the only credible and negotiable plan on the table that delivers no hard border in Northern Ireland and also delivers on the vote of the British people".
According to the proposal, frictionless trade in goods between Britain and the EU could be maintained through a new free trade area.
Tusk hoped that substantial progress over Brexit talks with Britain could be made in October this year.
"The moment of truth for Brexit negotiations will be the October European Council (summit)," Tusk said.
"In October we expect maximum progress and results in the Brexit talks. Then we will decide whether conditions are there to call an extraordinary summit in November to finalize and formalize the deal,"he added.
Should the extraordinary summit take place, it would be on November 17-18, according to Tusk.
In addition, the 27 EU leaders reconfirmed that "there will be no Withdrawal Agreement without a solid, operational and legally binding Irish backstop".
"We continue to fully support (EU chief negotiator) Michel Barnier in his efforts to find such a model," the president said.
The negotiation of Brexit could be tough in October as EU and Britain are both defending their positions.
"It must be clear that there are some issues where we are not ready to compromise. Firstly, of the four fundamental freedoms, the single market, this is why we remain skeptical of Chequers," Tusk said.
"The Irish question remains our priority too and for this, we need not only goodwill, which we feel, the atmosphere was better than two or three weeks ago, but the Irish question needs something more than good intentions," he noted.
If an agreement is to be finalized by March 29, May and other EU members states leaders need to find an acceptable compromise for a solution in coming weeks so parliaments have enough time to ratify the agreement.
However, the gaps between Britain and EU is not easy to be bridged while time is running short.
"We need to compromise on both sides," Tusk noted. The decisive phase would be the Oct. 18-19 summit in Brussels, where Tusk wants a substantial breakthrough.
There is actually the risk of failing to get the deal ratified by parliaments before Brexit Day.
After two-day summit, German Chancellor Angela Merkel said "it was clear today that we need substantial progress by October and that we then aim to finalize everything in November."