(By convention the Lords will not delay legislation which has such a mandate.)
A bullish PM press conference with attention-grabbing promises does not - strangely enough - change this constitutional position.
The Commons can keep going as long as it can this evening but Lords is not obliged to give way.
It may give way, but it is not obliged to do so.
The correct resolution to this problem would be a general election, where the government can seek a mandate for the delayed Bill.
(Ho, ho.)