I suppose that it's possible. I guess that, if the Minister says he will do it, he probably means it at the time. The Guardian reports:

The Liberal Democrats today promised an attack on those who have made tax evasion a lifestyle choice, as the party announced government plans to raise an extra £7bn by 2014-15 by tackling tax avoidance and fraud.
The Treasury would be "ruthless with wealthy individuals and business who think paying extra tax is an optional extra", vowed its chief secretary, Danny Alexander.
Much of the clampdown will involve more intensive scrutiny of those liable for paying the new 50p tax band introduced by the Labour government. Revenue and Customs currently looks at 5,000 high net-worth individuals, but will expand that number to 150,000.

Aye weel. Let us see. Is Her Majesty's Customs and Revenue department in a position to launch an all out attack on tax evasion? Given that trained tax inspectors do not grow on trees and are difficult to retain, particularly in the demoralised civil service of today, and given that the department's staff numbers have declined by some 25% since 2005, there is room to doubt whether this exercise involves any more than good intentions. But if the Minister says it will be so, then let us hope he means it ...