The Pensions Regulator director June Mulroy has announced she is stepping down from her role at the watchdog after seven years.
Mercer has slammed the government for its handling of auto-enrolment, criticising ministers for turning a "deaf ear" to employers needing clarity over the new duties.
The Pension Protection Fund 2012/13 levy determination has been set at £550 - the lowest ever demand.
Pressure to prepare properly for auto-enrolment is mounting on employers and those who have not yet thought about it must act now, Fidelity says.
There is "scope for tremendous confusion" if trustees try to comply with all of the defined contribution principles and initiatives currently in operation, a consultant says.
The Pensions Regulator has laid out six principles for defined contribution pensions to address the currently "mixed" standards across the market.
Mercer has called on The Pensions Regulator to clarify trustees' role in an economic environment where low gilt yields are distorting funding levels.
Jack Jones talks to Margaret Snowdon
The Pensions Regulator has moved to reassure employers auto-enrolment plans will remain on track after government's announcement enrolment dates will be delayed.