The Prime Minister negotiated a Brexit deal with the European Union. This deal was rejected by Parliament, and there is currently an impasse in Parliament, predominantly due to significant concerns around "the Backstop" arrangement which features in the Prime Minister's deal.
You may be interested in these active petitions
When Article 50 Lisbon Treaty is engaged, the mandatory time limit for leaving the EU is 2 years.
In circumstances whereby Article 50 itself stipulates an ultimate 2 year time limit, there can simply be no argument that the Backstop should exceed this limit. The EU's member states previously agreed that this was a reasonable period for departure, so the Backstop cannot, on any analysis, supersede Article 50's own time limit. Such a time-limit would provide certainty and keep minds focused.