Sally Rooney could face legal proceedings after pledging to support Palestine Action.

The Normal People author wrote an essay in which she outlined her support for the proscribed group and promised it financial backing with royalties from the BBC.

The Government banned Palestine Action in July, and support for the group including funding, can carry sentences of up to 14 years in prison.

While Ms Rooney is based in Ireland and stated her views in the Irish Times, legal experts believe she could be liable for prosecution under British anti-terror law.

If it is suspected that Ms Rooney committed an offence under the Terrorism Act 2000, the best-selling author could face legal trouble should she travel set foot in the UK.

Ms Rooney has been reported to police in the UK, and campaigners have pledged to pursue a private prosecution if the pro-Palestinian writer travels to Britain.

The Campaign Against Antisemitism told the Telegraph that it will look into this means of prosecution should the authorities fail to act.

The group added in a statement: “Sally Rooney’s announcement that she intends to fund a proscribed terrorist organisation is utterly indefensible. This goes far beyond political activism — it is a deliberate statement of intent to channel money towards a group that vandalised RAF jets and terrorised the Jewish community.

“Platforms and publishers profiting from her work must urgently review their relationship with her, as they now risk enabling the flow of funds to a terrorist organisation. We have reported this matter to Counter Terrorism Policing.”

The police could take action, according to terror law expert Ali Naseem Bajwa KC, who works with law firm QEB Hollis Whiteman.

He said that terror law has “extra-jurisdiction reach”, which means that even “if Sally Rooney committed the relevant act of inviting or expressing support for Palestine Action outside the UK, she could be prosecuted within the UK” under sections of the Terrorism Act 2000.