There can be moments of high jeopardy in Parliament when Westminster holds its breath to await the outcome of a crucial debate that could determine a government's future.

In the end this didn't feel like one of them, but that doesn't mean Sir Keir Starmer has escaped unscathed.

Ultimately he won the vote pretty comfortably with a clear majority of MPs rejecting the idea that he should be referred to a parliamentary committee for investigation over his statements about Lord Mandelson's appointment as US ambassador.

But beyond the headline win, this was not a victorious moment.

No 10 expended considerable political capital in keeping its troops onside.

There was a ring-round by cabinet ministers, interventions from Labour big beasts including the former Prime Minister Gordon Brown, and Scottish MPs were called back from the campaign trail to bolster the ranks – all signs that Downing Street doesn't feel it can automatically count on the loyalty of its own MPs.

There was undoubtedly support from some Labour backbenchers, pointing to ongoing work to shed light on the process surrounding Lord Mandelson's appointment and rejecting the notion another inquiry was necessary.

Others said opposition parties were playing political games ahead of crucial elections, something denied by the Conservatives who insisted this was about the integrity of parliament.

In the end, 14 Labour MPs voted against the government, and while they were predominantly people who've previously criticised the prime minister, some of their interventions were scathing.

There was particular anger at the fact Downing Street had whipped its MPs in an attempt to guarantee their backing – with one claiming Labour backbenchers could be accused in being complicit of a "cover-up".

Ultimately Downing Street chose not to take a risk and deployed the full weight of the Number 10 operation to rally MPs.

For some it was savvy to avoid a referral to the same committee that was instrumental in the downfall of Boris Johnson, for others it was a heavy-handed approach at a time when Downing Street doesn't have political capital to spare.

There will be relief in No 10 that there won't be another parliamentary committee poring over every detail of Sir Keir's decisions and subsequent statements about the Lord Mandelson saga.

The post-vote spin from government insiders was undoubtedly an attempt to be positive, with one saying it showed the Parliamentary Labour Party was still "pretty together", though they added "for now".

Among Labour MPs there was no sense of jubilation at having seen off a challenge from opposition parties, rather a weary resignation and deep frustration that this issue keeps consuming parliamentary time and public attention when they would much rather be talking about something – anything – else.

Sir Keir might have won the vote in Parliament, but each time the issue of Lord Mandelson's appointment arises again he risks losing more authority among his own MPs.