The government has been urged to “act decisively” to secure the freedom of a British couple detained in Iran.

Craig and Lindsay Foreman, both 52, were on a “once-in-a-lifetime” trip around the world when they were arrested by Iranian authorities in January and later charged with espionage – something the family denies.

Following a meeting of the all-parliamentary group for arbitrary detention and hostage affairs (APPG), the couple’s son Joe Bennett told the BBC he wanted the UK government to be “really pressing” Iran for their immediate release.

The Foreign, Commonwealth and Development Office (FCDO) says it continues to raise the case directly with the Iranian authorities.

Mr Bennett said the meeting had reassured the family they had support, but he would still continue to pressure government to “make sure that what can be done is being done immediately”.

Iran’s government has been approached for comment.

Brendan O’Hara, APPG vice chair, told the BBC it was “absolutely outrageous” that Mr and Ms Foreman, who were just on holiday and have “no political connection”, had been “taken hostage”.

The Scottish National Party MP called the couple from East Sussex “innocent victims of a geopolitical power struggle”, likening them to “bargaining chips” between states.

“The UK government has to act and it has to act decisively”, O’Hara said, urging officials to do “everything they possibly can” to secure their freedom.

He pointed to the case of Nazanin Zaghari-Ratcliffe, a British-Iranian national who was held hostage by the Iranian government for six years to pressure the UK to pay a long-standing, multi-million-pound debt.

Haydee Dijkstal, a barrister representing the family, told the BBC there were concerns the human rights of the couple were not being fully protected in Iran.

She said they had been held in solitary confinement for more than 30 days and did not know what they were being charged with for several months.

Mr Bennett said he had not spoken to his parents for more than six months.

The FCDO advises against all travel to Iran.

“British and British-Iranian dual nationals are at significant risk of arrest, questioning or detention,” it says in its Iran travel advice.

“Having a British passport or connections to the UK can be reason enough for the Iranian authorities to detain you.”