With the NHS drug bill topping £10 billion in 2013, this investigation examines the tactics employed by drug companies to tap into that lucrative market and influence which medicines your doctor prescribes. Strict rules govern drug company spending in the UK, but still they pay out millions to doctors to attend and speak at conferences. Panorama goes undercover to see this subtle persuasion at work and asks whether you should have the right to know who is paying your doctor. And as Britain's most profitable drug company, GlaxoSmithKline, waits to hear whether it will face criminal charges following allegations of bribery in China, the programme reveals new evidence that GSK was recently paying doctors to boost prescriptions much closer to home, in Europe.