Reaffirming the firm’s dedication to the mid-market, Mr Shaw emphasised the importance of mid-sized businesses as the “economic engine” of UK economic growth.

In Scotland, there are nearly 2,000 mid-sized businesses generating £80 billion in revenues. UK-wide, the mid market is responsible for one in three private sector jobs and has revenues equivalent to half the value of UK GDP.

Despite this vital role, Mr Shaw says that the mid market risks being overlooked and undervalued by policy makers and that, with the right support from government, mid-sized businesses will play a central part across all regions of the UK in its ambitions for economic growth.

He also used his day one message to emphasise the importance of its network of offices to BDO’s future success.

“We are proud of our network of UK offices and the knowledge and market understanding of those who work there. Our close connection to local markets allows us to make a difference to growth benefiting local economies,” said Mr Shaw.

Welcoming Mr Shaw’s appointment, Martin Gill, head of BDO in Scotland, said: “The growth of our Scottish practice is a reflection of BDO’s growth and investment as a firm overall.

“Our core market of mid-sized, ambitious and entrepreneurially-spirited businesses has demonstrated strength and resilience during a challenging economic period.

“It is an exciting time for Mark, the new leadership team and everyone at BDO as we build on our heritage while looking to the future.”

Mr Shaw said: “It is a privilege to be taking on this role from my predecessor, Paul Eagland, who has now served his maximum two four-year terms. The firm’s growth and development during that time has been extraordinary.

“On behalf of all at BDO, I extend to Paul and his leadership team my sincere thanks for their hard work and their outstanding success.”

Mr Shaw added: “I look forward to working with our talented partners and colleagues to achieve balanced growth over the coming years; one that puts serving the public interest, our culture and the wellbeing of our people at its heart.”

He takes on the role at an exciting time for BDO. The firm, which has 18 offices across the UK and employs 8,000 people, is fast approaching the £1bn revenue milestone. This has been done through controlled growth across all parts of the business.

Last year, BDO also invested £120m back into the business - the largest annual investment in the firm’s 100-year history – with a clear focus on people, quality and future high-growth services.

Today also marks the commencement of a new leadership team at BDO. Announced this summer, the 11-strong team brings together new and existing leadership team members, combining continuity and stability with fresh and diverse perspectives. The firm will now operate across four core divisions – audit, tax, deals, and consulting, risk & outsourcing.