According to Article 20 of the Treaty of Lisbon, EU citizenship is additional and separate to national citizenship. Presently, there are no provisions for removing this citizenship and its associated rights from individuals, regardless of whether their nation leaves the EU.
The pair were the only candidates in the yes-no question of whether Momentum should endorse them.
Boris Johnson had suggested a public fundraising drive to pay for the bell to ring to mark Brexit.
Overall, the number of applications finalised by the end of December was more than 2.45 million.
The shadow business secretary would narrowly beat Sir Keir Starmer, according to a survey of Labour members.
It comes after Labour pledged to give 16 year-olds a vote in a second Brexit referendum.
Meanwhile fellow Labour leadership candidate Lisa Nandy said US trade deal should be contingent on Trump not dumping Paris climate agreement.
The successor to Mr Corbyn will be announced on April 4 after members and other supporters cast their votes.
"As long as it's your wish to stay with us, the European Union will always be your home"