Of late we have heard the phrase often in British media: 'Resigned the whip', 'resigned the Tory Whip', 'resigned the labour whip', 'resigned the UKIP whip', 'resigned the Lib Dem whip'. At first I thought it meant the Party Whip resigned: 'Resigned the party whip', as in 'Did quit the party whip'.
The Principles and Research
Either way, I searched the phrase to no avail, until finally I decided to analyse occurrences of the offending Britishism.
Firstly, I found it was not the Party Whips resigning. Not only that, but in many historic instances several people resigned the party whip at once.
Less reliable but more direct, at the Bottom of one of the recent articles someone had asked what a 'resigned the party whip' was, in the comments section, and a polite person answered that it was not the Whip who resigned. Rather, someone had resigned their position in the party representation. This was certainly the meaning conveyed in the historic uses I looked into.
Further, a party whip according to the Oxford Dictionary is the disciplinary official of a party (a meaning which also carries over here in South Africa), however it also means the elected representation of a party in parliament, which I think is what the British press are getting at and into:
'2 an official of a political party appointed to maintain parliamentary discipline among its members, especially so as to ensure attendance and voting in debates.(Emphasis mine)
British a written notice from a whip requesting attendance for voting. See also three-line whip.
(the whip) British membership of the group of MPs that form the official, elected representation of a particular political party, together with the duties or rights associated with such membership:
he resigned the Tory whip in protest at mine closures'
In applying these to the question of 'What is the meaning of the phrase: he resigned the whip'?
It does not mean that the whip resigned.
It does not mean the whip resigned him or her.
It does not mean someone resigned from the position of the whip.
It does mean he or she, being a MP: that is to say: being a Member of Parliament, quit (resigned) the membership of the 'official, elected representation of a particular political party, together with the duties or rights associated with such membership' (Oxford above).
SO there it is...