The US business employs about 45,000 people in 65 countries, a workforce which has ballooned 60pc from 28,000 people in 2018.
Recent efforts to trim its headcount include a voluntary notice period scheme targeting consultants across McKinsey’s UK and US offices.
Under the terms of the scheme, UK employees can spend nine months looking for new jobs while receiving full pay.
It follows sweeping job losses under one of the largest restructurings in McKinsey’s 98-year history, dubbed Project Magnolia.
The overhaul announced last year eliminated 1,400 jobs in back-office and support functions, including human resources, communications and IT.
The layoffs reportedly attracted criticism from among the company’s 750 senior partners who accused Bob Sternfels, global managing partner of the firm, of mishandling the process.
McKinsey, which recorded $16bn (£13bn) of revenue last year, is often called on by companies and governments needing help cracking their toughest problems.
However, the business has since warned 3,000 consultants that their performance is unsatisfactory and needs to improve.
Underperforming employees typically have three months to improve before being counselled to leave the business altogether.
The slowdown has also forced McKinsey to cut the number of new people promoted to its partnership and to defer partner bonuses.
