Boris Johnson has claimed his Brexit plan is a "genuine attempt to bridge the chasm" with the EU.
Speaking in the Commons, he said he had had "constructive calls" with EU leaders in the last 24 hours, including with European Commission president Jean-Claude Juncker, Irish Taoiseach Leo Varadkar and German chancellor, Angela Merkel.
Among his Brexit proposals - which focus on avoiding the Irish backstop - is an all-island regulatory zone in Ireland, which would eliminate the need for border checks when trading agri-food and manufactured goods.
This would come into force during the transition period, with the consent of the people of Northern Ireland.
WATCH: Boris Johnson updates MPs on Brexit negotiations
And at the end of the transition period, Mr Johnson insisted Northern Ireland would leave the customs union "whole and entire", along with the rest of the UK.
"There can be no path to a deal except by reopening the Withdrawal Agreement and replacing the so-called backstop," he told MPs.
"As I stand here today, we are some way from a resolution. It is to the credit of our European friends they have accepted the need to address these issues."
Mr Johnson insisted the UK government had shown "great flexibility" with negotiations, and that the proposals "go the extra mile as time runs short".
"If our European neighbours choose not to show a corresponding willingness, we will have to leave on October 31 without an agreement," he said.
But Jeremy Corbyn was not impressed with the plans, calling them a "rehashed version of previously rejected proposals".