Critics are harshly condemning the tightening of economic regulations.

Literal

Critics [topic-は] economic regulation [possessive-の] strengthening [object-を] fiercely criticizing [progressive-ています].

激しく非難しています — 激しく ('fiercely') intensifies 非難する ('to condemn'). 経済規制の強化 is a dense compound: 'strengthening of economic regulation.' ています marks the ongoing nature of the criticism.