He has warned against a rushed response to the controversy over the taxing of private equity's profits, and he claims that greater accountability to staff and stakeholders is the best way forward.
In his speech to the annual TUC conference in Brighton, Mr Lambert said: 'It is important that private equity companies disclose more than they have been doing'. He added that 'clarity on what is actually going on' is necessary for employees and creditors 'before we spring off and come up with solutions'.
Mr Lambert went on to say: 'My feeling has always been that if it's a duck, tax it like a duck. If it's income, tax it like income, and if it's capital gains, tax it like capital gains'.
The CBI boss's comments came as unions backed a motion demanding tighter and more rigorous tax rules for both private equity and the people who often run such businesses while being non-domiciled in the UK — a situation, union members believe, that widens the gap between the poor and the super-rich.
On the subject of non-doms, Mr Lambert again recommended greater accountability: 'It is important that the tax system is fair and that there are no whacking loopholes. We need to know more about non-domiciles, about the benefits they bring, about their numbers'.
However, he went on to warn against 'slashing the income of high-earners through the tax system' - a move that he said 'would be disastrous and have serious consequences for growth and employment'.