Been trying to work out which minister resigned and returned under Blair. The only one that I can find that is slightly comparable was Mandelson who resigned after late disclosure of a home loan from a colleague and he got a new role in government 10 months later. An enquiry found he hadn't broken the ministerial code anyway but the publicity was having a detrimental effect on the government so he went anyway. Not sure if there's any other examples, certainly none where there was a clear breach and a reinstatement in less than a week.