Shadow chancellor John McDonnell has written to the chancellor to demand more information about talks taking place between the government and Saudi Arabia's state oil company.
Saudi Aramco is currently exploring its options for a flotation on a foreign stock exchange, and London and New York are the front-runners in the race to host the biggest stock market listing in history.
However, McDonnell wrote to Philip Hammond today to question a $2bn loan guarantee provided by the government to Saudi Aramco, Sky News reported.
McDonnell has urged Hammond to publish any correspondence the Treasury has had with UK Export Finance (UKEF), which is signing of the loan, on Saudi Aramco.
A government spokesperson said: “UK Export Finance works to increase UK exports by providing finance to overseas buyers of our goods and services. As part of this, we will be providing Saudi Aramco with support in the form of credit guarantees to procure from the UK. This builds on previous support for UK exports as part of Saudi Aramco joint venture projects.
“In the coming months UKEF will be running a series of exporter events to help connect British suppliers with Aramco to fully realise the mutual benefits of this support.”