Labour sources are billing as a new offer, the party's UK leader will deliver the John P Mackintosh lecture for Edinburgh University.It comes as polls suggest Scottish Labour is floundering and could lose four seats next spring on current projections.A Labour official said: "The will be a major speech on devolution and the future of Scotland in a modern United Kingdom."This is about Keir showing himself as a future UK Prime Minister who values devolution and would further devolution in stark