And if so, what is the most appropriate political response to these mounting challenges?

In a 1996 report, former Postmaster General Marvin Runyon acknowledged the agency had mounting challenges.

A variety of groups are mounting challenges that could force ICANN to lose some of its power.

Others think he will struggle to win support for bold decisions needed to tackle the country's mounting challenges.

The SEC has faced mounting challenges to the constitutionality of how it appoints in-house judges in recent years.

But he faces mounting challenges, notably in Hong Kong, which has been rocked by protests demanding greater democracy.

The SEC has faced mounting challenges in recent years to the constitutionality of how it appoints its in-house judges.

But it warned of a drop in annual profit due to mounting challenges to its grain trading and processing business.

Many of those investors, as well as regulators, including New York's and Delaware's attorneys general, are mounting challenges to that accord.

She strongly rejected claims by the liquidators that the company should have stopped trading in July 2011 after mounting challenges including leaky building claims.

The High Court ruling could lead to other drug companies which have had their treatments restricted on the NHS also mounting challenges to the government.