The X Factor host is said to be training for a performance, which would see him team up with his Strictly Come Dancing rival at the awards ceremony, according to The Sun.
However, O'Leary is allegedly concerned about looking "daft" at the event, and is currently taking dance lessons.
A source said: "Dermot is game for a laugh but he is slightly concerned that Darcey and all her skills will make him look a bit daft.
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"He's no stranger to dancing and has made quite a thing of it on The X Factor.
"But doing something like the quickstep in front of millions of viewers is obviously quite a tall order."
On how the dance may play out, the source added: "On the night, Darcey will come on stage and then look to surprise Dermot by asking him if he'll join her for a dance.
"He could say no, of course. Viewers will have to wait and see what happens."
The National Television Awards air live on January 23 on ITV. Fans can vote for their favourite shows now on the NTAs website.
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