One of JP Morgan’s top investment bankers in London is facing fresh multibillion-dollar disappointment as his client decides whether to pull the plug on a $50 billion-plus deal.

Laurence Hollingworth, JP Morgan's head of industry coverage for corporates in Europe, the Middle East and Africa, is one of three London-based bankers advising pharmaceuticals giant AbbVie on its proposed $56.1 billion takeover of the UK drugmaker Shire.