The MP spoke of 'the slightly odd position where each DUP MP is worth more than Ronaldo"

Democratic Unionist Party MPs are now worth more than footballer Cristiano Ronaldo, an SNP MP has said, as the Government's deal with the Northern Irish party came under fire.

Alison Thewliss led the criticism of the Government's £1.5 billion confidence and supply arrangement with the DUP, as Labour also warned that trust could be eroded among other political parties.

Northern Ireland Secretary James Brokenshire insisted that the Government would remain impartial and continue to govern in the interest of all communities in Northern Ireland.

Speaking at Northern Ireland questions in the Commons, Ms Thewliss (Glasgow Central) said: "We're now in the slightly odd position where each DUP MP is worth more than Ronaldo.

"Does the Secretary of State agree with Jonathan Powell that it is now impossible for the UK Government to be even-handed in Northern Ireland?"

Fellow SNP MP Patricia Gibson (North Ayrshire and Arran) added: "Can the Secretary of State not see that the UK Government's credibility with the other constituent parts of the United Kingdom has been destroyed following this £1.5 billion bribe from Northern Ireland, subverting the rules of Barnett as the price of staying in office."

Mr Brokenshire rejected both suggestions, having earlier said the Government "remains steadfast in our commitment to the Belfast Agreement and its successors".

The Northern Ireland Secretary added: "We will continue to govern in the interests of all parts of the community and work in partnership with the Irish government in accordance with the well-established three-stranded approach, as we have done for the past seven years."

Shadow Northern Ireland secretary Owen Smith said: "I don't doubt for a minute the good faith of the Secretary of State and I wish him well in trying to bring about the power sharing executive.

"But he must acknowledge that his desire to look impartial has been compromised by the arrangements with the DUP.

"I'd just like to know what did he advise the Prime Minister about it? Did he tell her that she was making his life that much harder?"

Mr Brokenshire said there was nothing in the Belfast Agreement that stopped the Government from making deals with other parties in Northern Ireland.

Mr Smith replied: "He knows from his experience and mine that trust is absolutely vital in Northern Ireland and there is a danger that that trust between parties and in the Government will be eroded over time if one party is seen as having the ear of the Government."

Mr Smith also urged transparency over the deal in the future.

Mr Brokenshire said: "This issue of impartiality and the principle of working across all communities and with fairness to all communities is one that we steadfastly uphold, why I continue to work with and engage with all parties and indeed community groups and all sectors across Northern Ireland in the role that I uphold.

"I think that he has seen from the actions that we have taken in publishing the confidence and supply agreement, in publishing the financial statement that sits alongside, that that transparency has been provided."

SNP spokeswoman Deidre Brock said other parties in Northern Ireland had "very serious concerns" in the wake of the DUP deal, while Labour's Kate Hollern said the DUP deal "has been described as grubby, dangerous and desperate".

However, DUP deputy leader Nigel Dodds told MPs: "Can the Secretary of State be assured that our focus is on ensuring that money for infrastructure, health, education and the rest of it is spent equally and fairly across Northern Ireland, as has been our record in office in the last 10 years in the Northern Ireland Executive."

Mr Dodds sought to defend the deal, saying the DUP intended to tackle high suicide rates and severe mental health issues following a legacy of "terrorism and violence" in Northern Ireland.

Speaking during Prime Minister's Questions, he said: "Clinicians and others have pointed to the legacy of 30 years of terrorism and violence and the awful effects of that.

"Part of the money we are investing this week goes to mental health care - extra investment in the health service.

"Isn't it time that people recognised that this is delivery for all the people of Northern Ireland across all sections of the community and it is going to help some of the most vulnerable and disadvantaged people in Northern Ireland?

"People should get behind it and welcome it."