The Democratic Unionist party (DUP) has again denied that it is seeking financial incentives from the government in return for its support for the Brexit deal when it returns to the House of Commons next week.

A spokesman for the party said: “We are in discussions with the government to ensure Northern Ireland is not separated out from the rest of the United Kingdom as we leave the European Union. Contrary to some reports, we are not discussing cash. There are still issues to be addressed in our discussions.”

The initial announcement on Friday that talks were under way sparked speculation in Westminster that the party would seek to gain more spending pledges from the Conservatives, in addition to the £1.5bn that Theresa May agreed to spend in Northern Ireland to gain the parliamentary support of the unionists after the 2017 general election. The presence of the chancellor, Philip Hammond, in the meeting on Friday added further grist to the mill.

However, the DUP’s Westminster leader, Nigel Dodds, sought to dispel the rumours. “I would not read anything in that the chancellor was there other than he is a senior member of the government who is clearly involved in many of the issues we are talking about,” Dodds said.

“We are not discussing cash in these discussions; this is about Brexit and how we protect the future of the United Kingdom and protect Northern Ireland’s economic and political future.”

Dodds said that the chancellor’s presence in the meeting was to discuss the role of HMRC, customs and regulations in Northern Ireland.

Profile Who are the DUP? Show Hide The Democratic Unionist Party (DUP) is a Northern Ireland unionist political party, founded by Ian Paisley in 1971. The party is currently led by Arlene Foster. The DUP achieved their best ever general election performance in 2017, and have 10 of Northern Ireland’s 18 constituency MPs at Westminster, where they are led by Nigel Dodds. Since the election they have been supporting Theresa May’s Conservative government in a confidence-and-supply agreement. The DUP supported leave in the EU referendum, and have repeatedly expressed their concerns over the provisions for an Irish border backstop. This led to them voting against Theresa May’s Withdrawal Agreement with the EU in parliament’s three ‘meaningful votes’. Getting them to back any new Boris Johnson Brexit plan for the island of Ireland is seen as key to him getting parliamentary backing for a deal. Northern Ireland voted to remain in the EU. Devolution and power-sharing in Northern Ireland, where the DUP had held the position of First Minister since 2007, collapsed in January 2017, and has not been restored despite several attempts, most recently in the wake of the murder of journalist Lyra McKee. Martin Belam Photograph: Liam McBurney/PA

A key concern for the DUP is what the role of the currently suspended Stormont assembly would be in the event of the Irish backstop being used. The party is adamant that the assembly should have a veto over any regulatory difference between Northern Ireland and the mainland.

“A lot will depend on what the government is able to do to provide those guarantees that are necessary to assuage our concerns,” Dodds said on Friday. “We have pointed previously to our concerns that the government has deleted so far the paragraph 50 of the December joint report, which gave a lock and a provision for Northern Ireland in terms of what might happen in the backstop and the overall situation of the economic integrity of internal market of the United Kingdom.”

If the DUP decide to vote in favour of the Brexit deal, Downing Street is hopeful that Conservative Brexiters will also back it.