So a two-tier approach looks good in theory.

Organized labor has often fought the two-tier approach in the private sector.

He warned however that there was a "two-tier" approach emerging in terms of investors' attitude.

Because of Mr. Clinton's determination not to become engulfed by foreign policy, he has taken what some senior officials describe as a two-tier approach to the world.

He has supported retaining a two-tier approach to local government rather than allowing larger councils to become unitary authorities.

Meanwhile, union leaders are also coming under greater pressure to fight the two-tier approach.

"My intention all along was to go with a two-tier approach," she said.

Why are companies giving up the two-tier approach?

She sees less political risk in a two-tier approach that layers a private account on top of a modest basic benefit funded from tax revenues.

In the past, for instance in the airline industry, the two-tier approach has usually been short-lived.