The deal between May and the DUP has yet to be formerly agreed, but media in London reported that the State Opening will go-ahead even if no deal has been signed between the two parties.
Talks with the DUP on a deal to shore up the prime minister's minority administration are "progressing well", a senior Conservative source said.
He explained that the two parties are both committed to delivering Brexit, fighting terrorism, preserving the United Kingdom and boosting economic prosperity, giving a clue as to what will be included.
The opening was set to take place on Monday, but was delayed amid negotiations.
The state opening of Parliament was scheduled to take place on Monday, but has been delayed by prime minister Theresa May's efforts to strike a deal with the Democratic Unionist Party (DUP) to back her minority government, after she failed to win an outright majority in the recent general election.
Talks are still on-going between the Conservatives and the Northern Irish party to get their support for a Queen's Speech to be voted through next week.
The monarch is expected to attend Royal Ascot after delivering it.
There had been speculation she would miss a day of the famous event which is a staple of the Queen's calendar.
Meanwhile, the EU and United Kingdom government confirmed that Brexit Secretary David Davis and European Commission chief negotiator Michel Barnier will meet in Brussels on Monday.
Meanwhile, talks are continuing between the DUP and Conservatives, to secure the support of the DUP's 10 MPs in steering government business, including crucial measures on Brexit, through the Commons.
He said Mrs May must immediately create a cross-party joint cabinet committee to negotiate the UK's exit.
The Scottish and Welsh governments have also been vocal, calling for a clear agenda that would allow devolved administrations to consider relevant issues arising from the negotiations, such as the replacement of European Union funding schemes like the Common Agricultural Policy.
After announcing a date for the speech setting out Theresa May's legislative agenda, a Tory source said discussions with the Northern Irish unionists had been "progressing".