RBS’ sale of its Williams & Glyn unit – one of the key conditions it is required to fulfill after receiving a £46 billion bailout during the heart of the financial crisis – could be about to fail after Santander pulled out of negotiations to purchase it.

Talks between the two banks fell through after they failed to agree on a price for the sale of the Williams & Glyn network, the Financial Times reported on Tuesday evening citing “people briefed on the process.”