The six-month article 50 extension agreed by EU leaders is too long to increase pressure on MPs to ratify the withdrawal agreement quickly and too short for a major political change in Britain.
It does, however, offer the Conservative party enough time to elect a new leader and an enhanced incentive to push Theresa May out of Downing Street.
When May won a confidence vote last December, she became immune from another challenge to her leadership from her MPs for 12 months.
Those close to her insisted this week that her promise to step down before the next stage of Brexit negotiations meant she could remain in office until next year if the withdrawal agreement was still not ratified. But if top party figures such as 1922 committee chairman Graham Brady, chief whip Julian Smith and senior cabinet ministers were to urge the prime minister to resign, she would have little choice but to go.
Her potential successors have been on parade for weeks, forming campaign teams to persuade MPs to select them as one of two candidates who will go before the entire party membership.
May insisted after the summit in Brussels on Thursday morning that she would press on with her effort to win a majority for her Brexit deal and ratify it within the first three weeks in May. This would allow Britain to leave the EU on May 22nd, a day before it is due to hold European Parliament elections. But she acknowledged that the next few weeks would not be easy and that the fate of the withdrawal agreement now depends on the success of her government's talks with Labour.
Both sides claim that the talks are serious and constructive but there is no sign of a breakthrough and Labour negotiators complain that the prime minister is still refusing to budge from her red lines. Neither May nor Jeremy Corbyn command enough authority over their MPs to guarantee that a deal the both endorsed would win a majority in the House of Commons.
For now, neither the hard Brexiteers on the Conservative benches nor the ardent advocates of a second referendum on the benches opposite see any incentive to soften their positions. And the six-month extension agreed in Brussels will do nothing to change that.