I may be wrong, but I think it unlikely that Boris Johnson, Oxford Classics graduate and (euge!)  Mayor of London, will promise to "deliver". He isn't a postman, for God's sake. Dot Wordsworth shares my dislike of modern-day "deliveries" and of the "solutions" they contain:

'Twenty-five years ago,’ writes Mr Peter Gasson from Aylesbury, ‘policies were implemented; services were provided; changes were made or brought about; promises were fulfilled. Now they are uniformly delivered. I suppose the word has become so popular because it sounds emphatic.’ I know just what you mean, Mr Gasson, and so must we all, which suggests that politicians and managers who use the word deliver should think again. To give the cliché its full deficit of originality it is coupled with solutions: business solutions, catering solutions, heating solutions, bovine health solutions. All will be delivered, at a price.

By delivered they do not mean brought to your door in a cardboard box, like organic vegetables. They mean ‘done’. They will do what you pay them to. Very kind of them. Until recently, the most frequent use of the word deliver was in the phrase ‘deliver us from evil’. The word had come into English in the 14th century from French délivrer. The sense ‘liberate, set free’ had been conveyed by the Latin liberare (as in the Lord’s Prayer too). But in late Latin this meaning had been taken over by the emphatic deliberare, which in classical Latin had meant ‘to weigh well’. So I suppose there would have been a late Latin Dot Wordsworth (Punctilla Verbivalor?) complaining of the misuse of liberare.

We mothers are delivered of our offspring, and Henry II wanted to be delivered from (not ‘of’) the turbulent Becket. In Henry’s case, the words seem to have been put into his mouth by Robert Dodsley in a history book published in 1740, although the 12th-century chroniclers have him saying something similar. Anyway he would have spoken to the French-named knights in Anglo-Norman.

I had also been wondering whether highwaymen ever really said ‘stand and deliver’. The earliest use of the phrase found by the editors of the OED is in Alexander Smith’s History of the lives of the most noted highwaymen (1714). Smith’s series of lives of criminals proved very successful. It is disappointing, then, to find that nothing is known of the author, or even whether he was one man. As for the annoying modern sense of deliver, it comes from America, as many annoyances are sometimes unjustly suspected of doing. Fred Astaire in Steps in Time (1959) wrote: ‘I have a horror of not delivering — making good, so to speak; and I can’t stand the thought of letting everybody down.’ Perhaps this virtue is now so widely claimed because is it no longer widespread.