He said his party will not back a speaker or nominate ministers until the UK alters the Northern Ireland Protocol.
“Today the DUP will not support the election of a speaker in the Assembly,” he said in a statement to the News Letter.
Sir Jeffrey continued: “Some parties who just a few months ago were mocking the promise of decisive action from the DUP in relation to the Protocol are the very same parties now feigning surprise and outrage at a political party keeping its promise to the electorate.
“Devolution was restored on the basis of the ‘New Decade, New Approach’ agreement. We have seen delivery of, or significant progress towards nearly every aspect of that document except one.
“That is the UK government’s promise to legislate to respect Northern Ireland’s place within the UK internal market.
“Twenty-eight months since that promise was made and 16 months since it should have been delivered, unionists cannot stand accused of lacking patience.”
Sir Jeffrey vowed: “I have both patience and resolve in equal measure to see the Irish Sea border removed and stable as well as sustainable devolution restored.
“Unionist concerns on the Northern Ireland Protocol are not merely some political squabble which is impacting upon Stormont. The protocol is a direct challenge to the principles that have underpinned every agreement reached in Northern Ireland over the last 25 years. It erodes the very foundations that devolution has been built upon.”
Yesterday Michelle O’Neill, Sinn Fein vice-president and first minister in any new Executive, appealed to the DUP to join with all the other main parties at Stormont and nominate a speaker leading the way to a power-sharing administration.
The Assembly is due to have its first sitting today following an historic election result which saw Sinn Fein become the first nationalist or republican party to top the poll.
Ms O’Neill has once again urged the DUP to enter a new Executive.
Speaking at the Balmoral Show yesterday she said: “It is not acceptable or not good enough that the DUP won’t turn up or won’t nominate for the position of speaker or the title of first or deputy first ministers.
“The public here that I’ve been speaking to today want an Executive, want an Assembly. They want it working for them, they want money in their pockets to deal with the cost-of-living crisis and we can do all of that whilst trying to make the smooth implementation of the protocol.
“We will not be held to ransom by the Tory government, their internal fights between their own members.
“We are all being held to ransom here and that is not acceptable.”
She added: “I think it is incredulous that the DUP would even consider not nominating.
“The public here just voted in an election – they voted for politicians to work together, they voted for political parties to work together to put money in their pocket to deal with the cost-of-living crisis, to start to fix our broken health service.”
On the DUP’s refusal to nominate Ms O’Neill added: “I don’t think that is acceptable when they have just been before the electorate and the people have voted to have politics working for them.”
Paula Bradshaw, Alliance Party MLA for South Belfast, described the DUP’s veto on the speaker and over all the Executive as a “shameful subversion of democracy” adding that “it merely demonstrates the veto system is no longer fit for purpose and should be swiftly abolished”.
The trade union movement has expressed concern that the Executive has not been formed at a time of the cost-of-living crisis and with workers forced to take industrial action to get pay that matches rising inflation.
Owen Reidy, assistant general secretary of the Irish Congress of Trade Unions, said: “Refusing to form an Executive in this instance does not in any way address or alter issues around the protocol.
“Refusing to establish a Northern Ireland Executive on this occasion is wrong, as it was wrong on the last occasion. The time for the restoration of the Executive is now.”