The multibillion-pound deal to deliver nuclear powered submarines for the UK and Australia is facing questions just four years into the decades long plan.

In the UK there are amber and red warnings for building the boats and propulsion systems, for its part the US is struggling to build enough Virginia class subs, and Australia faces a monumental challenge to be ready for its first nuclear vessels.

So will the Royal Navy be asked to do more in the Pacific for longer, while also having to wait for gaps in its submarine capability to be filled?

Kate and Mike are joined by former Royal Navy Commander Tom Sharpe and senior defence researcher Sophia Gaston to assess the risks, the potential consequences, and how they could be avoided or at least mitigated.