To clarify, this situation isn't mine, but a friend of mine whom I'd like to help. This is what I understand of it so far.
About 6 months ago my friend started a new job in a junior/mid-level position. Part of that job involves working with a slightly more senior colleague, getting authorisation from them to do things, and having them check my friend's work.
From day one this colleague has been very unresponsive; even before COVID when they were in the office, the colleague wouldn't respond to emails. My friend approached them about it personally; the colleague apologised and said that they were busy, but then nothing changed as a result.
With everyone working at home now due to COVID, this has been exacerbated. The colleague is practically unreachable; not responding to emails or IMs, not answering the phone, etc. This is making my friend's job difficult, as it's necessary to e.g. get approval from the colleague before things can progress.
I suggested that my friend tell a manager about it if it's making things difficult, especially since the colleague has already been approached by my friend personally about it and has done nothing. My friend did mention it to a manager, but nothing came about as a result.
Now my friend doesn't feel confident in getting help with this issue, because this colleague appears to be quite popular and well-liked in the office, including by some senior management, who may turn a blind eye to it.
The work not getting done reflects badly on my friend because it causes blockages and subsequent delays in getting other things done. I hope that people higher up see the problem and don't just blame it all on my friend.
I suspect that it is deliberate, because when the colleague wants something from my friend, they will suddenly start communicating.
In such a situation, how would you recommend dealing with this colleague?