Imran Khan won power in Pakistan two years ago with a promise to root out corruption and take on the country's vested interests. So how's it going? Rising food prices and the Covid pandemic have left many Pakistanis feeling worse off, while the anti-corruption drive has become a political battleground. Stephen Sackur speaks to Ishaq Dar who was Pakistan's Finance Minister and a key lieutenant of former Prime Minister Nawaz Sharif. Now both men are trying to rally opposition to Imran Khan, but how much credibility do they have?