という事実は否定できない

the fact that ... cannot be denied

→ と
phrase Rare #42,265
the fact that ... cannot be denied Used to state that something is undeniably true. The part before という事実 describes the fact being referred to.
JA: 彼が努力したという事実は否定できない。
EN: The fact that he worked hard cannot be denied.

彼らがここへ来たという事実は否定できない

The fact that they came here cannot be denied.

彼がそれをやらなかったという事実は否定できない

The fact that he didn't do it cannot be denied.

彼女がそれに関わっていたという事実は否定できない

The fact that she was involved in it cannot be denied.