Deloitte isn’t just environmentally friendly — the accountancy firm wants to be “dark green”. The company, based in London and with 21 other UK sites, is trying to source 10% of its energy from renewable sources such as wind or solar generators.

It makes a real effort to support employees in their work for good causes (a 76% positive score), with more than a quarter of its 10,767 people using the give as you earn scheme, and the organisation matching their contributions. As an incentive, it offers a monthly competition for all scheme members to win tickets to destinations such as Sydney, Rio de Janeiro and New York.

Other charitable initiatives include Skills4industry, helping more than 500 young people in disadvantaged communities into employment. The Deloitte Foundation, the company charity, is investing a further £2m in the scheme in the next five years, as well as creating a disability sports institute, assisting disabled athletes to world-class performance. At the end of each working day, the subsidised staff cafes work with the charity Fairshare to give excess food to the homeless and the needy.

Employees think the firm makes a positive difference to the world (57%), does its bit to protect the environment (52%) and support its local community too (58%), the latter a top five score among the big companies in our list.

The partnership was created in 1899, and last year’s profits were £460.9m. As with other large companies, this funds a generous flexible benefits programme, in which staff can select private health insurance for themselves and family members, dental insurance, critical illness cover or car allowances. People can also use the “bikes for work” scheme, giving the equivalent of up to 50% off a bicycle for commuting.

Everyone has a contributory pension, life assurance, access to loans and an employee assistance service, plus discounts on various goods and services. Holiday is 25 days for all staff members, but people can buy another five days through the flexible benefits system. After three years, they can take a career break of 104 weeks unpaid, and 269 people are currently using this.

Flexible working is available, and paternity benefits are slightly increased with one week at full pay. Mothers have six weeks on full pay, 20 on the statutory minimum and 26 unpaid.

John Connolly, senior partner and chief executive for the past seven years, runs Deloitte on sound moral principles (72%) and people have confidence in the leadership skills of senior management (79% and the second highest score on this point). One of the company principles is that: “We operate within the letter and the spirit of applicable laws.”

In November 2005, Connolly began a series of nine regional events to explain his own priorities and get staff feedback. The company surveys employees and takes their comments into consideration in providing new benefits.

People grow personally at work (82%), and their muscles do, too, with yoga classes and a health pod providing massage and reflexology. The firm is investing £80m in a new “campus”, with a modern gym, learning zones, relaxation places and a bicycle garage — and all this with as little impact on the environment as possible.

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