Over 65 people who work for Grant Thornton, including the firm's recently appointed CEO Sacha Romanovitch, abseiled down the nine storey, 190ft building throughout the day.

The firm is hoping that the challenge will raise £25,000 for the charity through sponsorship and other activities outside the building on the day, including bucket collections and a candyfloss machine.

Ian Smart, London managing partner at Grant Thornton, said: "Every year thousands of families rely on support from Great Ormond Street Hospital. We wanted to do something a bit different and challenge ourselves in order to raise lots of money for this fantastic charity. The money raised will help the hospital continue to deliver world-class care for very sick children and their families from across the UK. I'm really excited to be taking part and encourage everyone to give generously."

Rachael Willis Fleming, head of account management at Great Ormond Street Hospital Children’s Charity, said: “We would like to say a big thank you to everyone at Grant Thornton who is taking on this incredible abseiling challenge.

'Everyone involved will be helping us make a real difference for Great Ormond Street Hospital’s young patients, raising vital funds to help us rebuild and refurbish the hospital, fund research into better treatments and provide up-to-date equipment and vital support services for families.”

To donate please go to Justgiving.com or text GTUK 75 £2 to 70070.