PETER Russell’s letter (August 5) berating possible successors to the current First Minister – even though I understand there is currently no vacancy – faces a major problem in that if you suggest Ms Sturgeon might be hit by a bus, you really do have to name a replacement, a successor. Mr Russell is too wrapped up in pointing to the unsuitability of those he identifies as possibilities, and while I will sign up to his view of Derek Mackay, I find his rejection of the others too contentious to be dealt with in a single letter. Moreover, those who have not come between his crosshairs include Joanna Cherry, Tommy Sheppard and Kate Forbes (who has been sure-footed in the Finance Secretary post).

But what is most interesting of all is that Mr Russell never gets round to which member of his own party might be best suited to slay the SNP dragon? Perhaps Richard Leonard? Maybe Jackie Baillie? Or perhaps Monica Lennon? Or maybe, like the Conservatives, Mr Russell would look to someone from his own party sitting for a Scottish seat? So, perhaps Ian Murray, and if not him there is always …eh …err … well, Ian Murray.

One thing both Mr Russell and Allan Sutherland (Letters, August 5) have missed is that since 2011, the Labour Party has had five leaders, while the Conservatives are turning to their fourth. Those positions seem to be the antithesis of the stability that Mr Russell habitually insists the Scottish electorate crave. He avers that “devolution has diminished Scottish politics”, but it seems more likely the Unionist parties have diminished themselves.

Alasdair Galloway, Dumbarton.

IAIN Macwhirter suggests “a new formal Act of Union to cement the new post Brexit relationship” ("How a New Union could keep us living apart together", The Herald, August 5). It would be between all four of the UK's constituent parts.

For Scottish unionist parties it offers a genuine option with lots of opportunity for developing realistic proposals and suggestions.

Intriguingly it could also help inform any public debate and provide a realistic and intriguing option for a multi-choice referendum after next year’s Scottish Parliamentary elections.

Foster Evans, Renfrew.

I READ with interest Allan Sutherland’s letter (August 5).

I admire the sincerity with which he expresses his views, such as “moral victories ... are failures” and his support for “Downing Street poking its nose in”. He praises Douglas Ross for proposing to scrap the Curriculum for Excellence (a Lab/Lib coalition initiative, the implementation of which I was working on for two years prior to my retirement as depute head teacher in 2007), and suggests he drags the pool of Tory talent by inviting on board defeated (but “talented”) former MPs. His arithmetic regarding the views of the Scottish electorate quite dazzled me – obviously the vast majority are anti- independence – and George Galloway’s plans A and B (and all the way to Z) will obviously save the Union. He finishes with a flourish – an appeal to the powerful forces of Labour and the LibDems.

I am left with only one question.

What planet is he on?

Jean E Park, Irvine.