"unduly restrict" is grammatically correct and can be used in written English.
It means to impose limitations or constraints that are excessive or unreasonable. Example: The new regulations unduly restrict the rights of artists to express themselves freely in public spaces.
Carol Sanger believes these laws unduly restrict women's autonomy and violate the constitutional guarantee of liberty.
Or retaining nanny state classification standards which unduly restrict what grown-ups may read or watch?
But his supporters said house arrest could unduly restrict his access to people, his business and his political activities.
Because the lymphatic system in the chest wall drains via both the internal mammary and axillary nodes, it seems that this practice might unduly restrict venous access options.
Thus, to adopt respondents' construction would unduly restrict the Commission's power to carry out one of the major policies of the Act.
'Their Lordships nevertheless recognise that too rigid adherence to precedent may lead to injustice in a particular case and also unduly restrict the proper development of the law.
Plans may be keeping costs low by unduly restricting access to the drugs they cover".
His students had to ask and answer, for example, What should regulators and Congress do to protect our financial system from a crisis without unduly restricting economic growth?
The Court's ruling does not establish parity between federal and state prisoners; rather it unduly restricts the power of the federal courts to remedy substantial injustice.
But Kennedy was extremely receptive to arguments that the government had unduly restricted freedom of speech — especially in the area of campaign finance.
Critics contend that Judge Hudson has unduly restricted Congress's authority to regulate interstate commerce, the principal basis on which the government defends the law.
