The DUP has urged Northern Ireland Secretary Julian Smith to reinstate a portrait of Queen Elizabeth II at Stormont House.
It emerged last month that the portrait had been removed from the Northern Ireland Office base in Belfast after compensation was paid to a civil servant over it.
Lord Ken Maginnis, former Ulster Unionist Fermanagh and South Tyrone MP, told the House of Lords that a civil servant had been paid £10,000 (about €10,980) in compensation for being offended at having to walk past portraits of the head of state and her husband, the Duke of Edinburgh.
On Wednesday night Mr Smith revealed there is a photograph of the queen in his office in Stormont House.
However, unionists have urged the Northern Ireland Secretary to reinstate the portrait of the Queen.
DUP MP Gavin Robinson said Mr Smith “needs to act”.
“Whilst the Secretary of State Julian Smith has a small photograph of her majesty the queen in his office, this does not address the wider issue. He needs to act,” he said.
“The DUP has raised this issue with the prime minister and the Northern Ireland Secretary of State.
“There should be a sensible approach to issues like this. The portrait should be reinstated forthwith.
"The Northern Ireland Office should reflect the reality that it is a branch of the United Kingdom government. There is no shame in that.
“I will also be working to understand the full context of how this position came about, how it was resolved in this way and how a similar situation would be handled in the future.
“The public deserve answers.”
‘Symbol of sovereignty’
Ulster Unionist MLA Doug Beattie said that given that it represents the head of state, a portrait of the queen is a "symbol of sovereignty and not identity".
"The Ulster Unionist Party respects the right of all our citizens to declare their identity to be British, Irish, or other; all should be respected equally. That was a core commitment in the 1998 Belfast Agreement, which enshrined the principle of consent," he said.
“The sovereignty issue was settled by public referendum in 1998 following the agreement and given legal status by the Northern Ireland Act, 1998.
“As Stormont House is the official residence of the Secretary of State for Northern Ireland, and HQ of the Northern Ireland Office locally, it is only fitting that portraits of her majesty should be on display there to both reflect and respect the constitutional reality of the sovereignty of the United Kingdom in Northern Ireland.” – PA