The preselection hopes of controversial Turnbull government minister Concetta Fierravanti-Wells have been hit by allegations she broke a promise not to employ a key Liberal Party executive and factional ally.

The hard-right NSW senator hired as an electorate officer Nathaniel Smith, a Kogarah councillor and the son of former NSW attorney-general Greg Smith, who also serves on the party's state executive.

Concetta Fierravanti-Wells staffer Nathaniel Smith, right, meets Lord Christopher Monckton Credit:Facebook

Liberal sources accused Senator Fierravanti-Wells of breaking an explicit promise to senior party figures that she would not employ Mr Smith or run a "factional office".

She is also accused of trying to conceal Mr Smith's employment by demanding his removal from her staff list and denying him a parliamentary email address.