Will Theresa May's decision to sack Gavin Williamson come back to haunt her? That's the question being asked in Westminster this morning after the Prime Minister fired the Defence Secretary alleging that he was behind a leak on Huawei from a meeting of the National Security Council to the Telegraph. The hope in No. 10 was that this decisive action would bring the episode to a close. That now seems rather optimistic.

News of Williamson's sacking has made its way onto the front page of every paper – but most of the articles suggest it's not a black and white issue. They all note that doubt has been cast over what evidence No. 10 actually has against Williamson and reference the fact that he has sworn on his children's lives he is not behind the leak. The Conservative politician's comments to various media outlets suggesting that the investigation amounted to a kangaroo court and that the civil servant in charge it – Sir Mark Sedwill – had a grudge against him are also widely covered. This means that attention is likely to turn in the coming days to Sedwill's own conduct. May will also come under pressure to push this matter on to a police inquiry. Opposition parties have been quick to call for one – as has Williamson, who believes it would clear his name.

There's another reason the decision to sack Williamson could backfire on Theresa May. The exchange of letters between the pair was brutal – with little love lost. Yet Williamson and May's relationship has previously been very close – with the former defence secretary playing a crucial role in her leadership campaign and going on to serve as her chief whip (where he arranged the confidence and supply agreement with the DUP in the wake of the disastrous snap election) and later defence secretary. Although the relationship has been under strain of late, Williamson was still someone No. 10 would reluctantly call on when May found herself in tight spots. When she faced a confidence vote by her own MPs, Williamson helped advise on how best to win it – and when talks with the DUP broke down earlier this year over the Withdrawal Agreement, Williamson was asked to try and clear up the mess.

Not only has May lost someone to help her in tricky situations (such as, say, renegotiating the confidence and supply arrangement with the DUP), that person is now on the backbenches where they could hold a grudge over their treatment. The fact that the main story one day on from the sacking is not how badly Williamson behaved but whether the inquiry had sufficient evidence suggests that this is already not playing out as Downing Street would have hoped.