Rachel Johnson has reportedly joined the Liberal Democrats, in a move which is sure to infuriate her brother Boris, the Foreign Secretary.
The Guardian claims that she has toyed with the idea of standing as a candidate - but may not have enough time to be selected.
It is understood she has joined the political party as a protest over Tory support of Brexit.
Ms Johnson was a member of the Conservative Party until 2011.
Unlike her brother, the columnist was a vocal supporter of the Remain campaign.
She has always maintained that despite her differences with the party, she votes for it out of "duty".
In her column last year, Ms Johnson wrote: "In general elections I have voted nothing but Tory, and since I have two brothers standing as MPs for the party, it’s sort of a matter of family duty."
My weepy Brexit column (went down like a bucket of cold sick) https://t.co/ouR2aB1eQZ— Rachel Johnson (@RachelSJohnson) June 26, 2016
The Lib Dems have declined to confirm her membership, because of data protection rules.
It is unlikely she will be able to stand as a candidate, as Lib Dem rules state one must have been a member for at least a year.
Jonathan Powell, candidly speaking truth to... blearrrghhh on Brexit https://t.co/vbEE3lWdXU— Rachel Johnson (@RachelSJohnson) January 4, 2017
However, they could support her as an independent candidate by not standing another against her.
If she stood, her house is near the constituencies of Yeovil and Bath.
She and her husband Ivo Dawnay may be now united in political points of view; last year she wrote that he “may now be creeping towards the Libi-Dems”.