What the Labour leader Jeremy Corbyn wears to this week's State banquet, held in honour of China's President Xi Jinping and his wife, has been the subject of intense speculation.
Will he don a white tie? Does he even own one?
The question of whether his wife Laura Alvarez will attend has been settled.
But there are certainly more significant issues at stake.
Mr Corbyn, it's believed, wants to raise the issue of China's human rights record. For the Prime Minister, strengthening economic ties is top of the agenda.
China is now the world's second largest economy and David Cameron hopes to promote Chinese investment here, while increasing our exports to China.
Some of that investment, however, is controversial. Senior military and intelligence figures are said to have warned Ministers about the prospect of China getting a big stake in Britain's nuclear power industry.
Paul Dorfman of University College London's Energy Institute, told the Times: "No-one else in Europe would cut this deal... The idea that the UK is prepared to do so is, frankly outstanding."
The recent downturn in the Chinese economy has also led some to question whether this is the right time to be looking to China to promote growth here.
The Chancellor George Osborne, on a recent trip to China, heralded what he said was a 'golden era' of cooperation between the two countries.
Fine talk, but whether it bears much relation to reality, is something we'll find out this week.