Wendy Askew replaces her brother in Senate

Wendy Askew has been approved to replace her brother David Bushby as a Liberal senator for Tasmania.

Wendy Askew has been approved to fill the casual Senate vacancy left by her brother David Bushby.

She will be the first Liberal woman to represent Tasmania in more than 20 years.

"The appointment takes effect immediately. Senator Askew will take the oath or affirmation of office when the Senate next meets on April 2," Senate president Scott Ryan said on Wednesday.