Vote Leave campaign leader Boris Johnson arrives to speak at the group's headquarters following the EU referendum. REUTERS/Mary Turner/Pool

LONDON (Reuters) - Former London mayor and leading Brexit campaigner Boris Johnson is the favorite to succeed David Cameron as Prime Minister, bookmaker Ladbrokes said in a statement on Friday.

Cameron said he would stand down by October after voters ignored his pleas to stay in the European Union and voted to leave the bloc in a referendum.

Ladbrokes quoted Johnson at evens, ahead of interior minister Theresa May at 3/1 and Justice Secretary Michael Gove at 5/1.