Increasing space for lyrics for one part of a verse

[Tom Dickson]

I have a verse that has a very long slur, and the lyrics run into the slur.
Technically, it's the dashes that are printed between the syllables. I'm able
to change the font for that part of the verse to italics, but I can't seem to
figure out what to use to increase the vertical spacing at that place.

Is it possible to increase the spacing there inside the lyricmode?