The war of words took over Thursday, as WPP, the marketing group, stepped up its efforts to buy Taylor Nelson Sofres, the market researcher, and so thwart a rival deal between TNS and Germany’s GfK – with both sides pledging to play “rough”, “tough” and “dirty”.

But there were facts, too: WPP’s third possible offer for TNS saw it lay out for the first time why this £1bn takeover would make sense for its own shareholders.