For the second time in the crisis over Iraq, Tony Blair is looking to the UN to bolster his position at home.
Blair needs Bush to support UN role
And the prospect of failing for the second time must be giving him sleepless nights.
The prime minister is desperate to see the UN at the heart of any post-war administration in Iraq - both handling the massive aid programme but, more importantly, ultimately running the country.
But he is battling against a hugely reluctant, or even downright hostile Washington.
The hard liners in the US quite simply are not prepared to accept that the body which, they believe, let them down in their historic campaign should take over once the shooting has stopped.
And this has led to fears that the US is determined to run Iraq for an indefinite period once Saddam is toppled.
In the lead
For the prime minister, there are just too many echoes here of the pre-war crisis which saw him ultimately abandoning the UN route - and inflaming the backbench rebellion over his support for war.
For months before the conflict, the prime minister insisted he would not go to war without a second UN resolution sanctioning it.
He also constantly expressed his confidence that he would get that vote.
Bush advisers reject UN
Winning that resolution would have effectively neutralised backbench opposition at a stroke.
But as resistance to such a resolution grew he trimmed and, when push came to shove, he abandoned it all together.
Now he is insisting that the UN must be in the lead in administering post-war Iraq.
Or at least he was. The language from Downing Street has already been finessed - and the talk now is of the UN "endorsing" the administration.
So once again, Mr Blair finds himself in Washington trying to persuade President Bush to go down the UN route - and, at the same time, get him off the hook.
He is well aware that his backbench rebels are preparing to regroup after the war.
They are insistent that the UN should be the driving force in Iraq after the war.
Ending up with a US run Iraq would, they claim, vindicate their suggestions that this had always been about US control.
This is the last thing the prime minister needs.
There are no signs at the moment that events in Iraq have persuaded his backbench rebels their concerns were misplaced.
If that remains the case and he then fails to win the post-war case, his position will be further undermined.