The phrase "a declaration that was" is correct and usable in written English.
It can be used when referring to a statement or announcement that has been made in the past.
Example: "The committee issued a declaration that was intended to clarify their position on the matter."
Alternatives: "a statement that was" or "an announcement that was".
Tajikistan, in a declaration that was typical of the genre, called meaninglessly for an "objective assessment".
The talks resulted in the nonbinding Copenhagen Accord, a declaration that was "noted" by other parties to the convention.
In a declaration that was partially unsealed on Thursday afternoon, Mark E. Mitchell, a senior Pentagon official, provided further details about the plan.
Last week we and 50 of our colleagues Palestinian and Israeli political and cultural leaders -- signed a declaration that was published simultaneously in Israeli and Palestinian newspapers.
Following a thousand-year-old tradition in Mesopotamia, Cyrus began his reign with a declaration that was issued and distributed on clay tablets, cones and cylinders.
When Valeri Belokon poured a few of his millions into Blackpool football club in 2006, he made a declaration that was met with no little laughter.
It's a declaration that's endearing and self-aware, just a couple of the qualities that make Dan & Phil's popularity easy to comprehend.
(Christian has since declared that he never intended to marry her, because marriage was against his Maoist beliefs — a declaration that is neither here nor there.
As the summit meeting formally began Monday evening, the nations still had no agreement on a declaration that is supposed to be issued by their leaders on Tuesday.
The BBC has today said it has "no intention" of charging for online news, in a declaration that is unlikely to please James Murdoch and his father Rupert as they prepare to start charging for News Corporation content on the internet.
