And they're off. Over the past two days Emily Thornberry and Keir Starmer have launched their respective bids for Labour leadership in the Guardian. Today it is Lisa Nandy's turn, with a big interview in the Daily Mirror.

The Guardian is the most obvious battleground for the contest. According to a YouGov poll, 44 per cent of Labour members have read the paper in the last 12 months, way out in front of the second-placed Observer on 26 per cent. It seems the Graun really does have a monopoly on the hearts and minds of the membership.

Meanwhile the Mirror — which is rumoured to be thinking of endorsing Nandy after political heavyweight Kevin Maguire spoke out in her favour — has only been read by 10 per cent of Labour members in the past twelve months. By point of comparison, that is below the Murdoch-owned Times (13 per cent) and only very slightly above the Financial Times (8 per cent).

Nandy's choice of the Mirror is symbolic. As one Labour MP supporting Nandy explained, Mirror readers are exactly the sort of voters the party needs to win back. The interview took place in Bury North — the most marginal seat in the country and only 20 miles down the road from Nandy's own constituency of Wigan. Nandy is signalling to the membership — which is overwhelmingly metropolitan and liberal —that it might be worth bearing in mind the entire electorate of the UK when voting for the next leader.

More than that, Nandy is reminding the PLP of the necessary diversity of Labour voters. If her campaign is to succeed, she will need to convince more than the 19 rebels who voted Johnson's deal through on second reading. Following the election, only nine of them remain. Every candidate needs 21 nominations from fellow MPs to get on the ballot paper.