Supporters of Islamic State of Iraq and the Levant (Isil) should not necessarily be criminalised, because it impinges free speech, a joint parliamentary Committee says.

A report released today will say that the bill “may criminalise curious minds and expressions of belief which do not carry any consequent harm or intent to cause harm.”

The Joint Committee on Human Rights says it has “serious concerns” with the new powers the government is proposing in the Counter Terrorism and Border Security Bill currently going through parliament.

The Committee, chaired by Harriet Harman MP and made up of MPs and Peers, is concerned that some of the new powers are too vaguely defined and do not have sufficient safeguards to protect human rights.

The report will warn that academic and journalistic research may be criminalised by the bill, as well as “inquisitive or foolish minds”.