The industrial action is over what the union says are plans to cut pay by 25 percent and shed four jobs from the 44-strong chorus.
Martin Brown of trade union Equity said all of those balloted had supported the action and predicted that the performance may not go ahead without the chorus.
"The opera world is appalled that this world-class choir is facing such pay cuts," he said. "We have had fantastic support from the arts world and audiences."
The ENO says it is facing a £5 million (6.5 million euro, $7 million) cut to the grant it receives from the government.
It said in a statement that it was "extremely disappointed" there had been a ballot for strike action before "serious negotiations".
"We are saddened that the action that they (Equity) have chosen seems specifically designed to cause the utmost harm to both the company and our audience," it added.
The ENO performs operas in English and, along with the Royal Opera House based in London's Covent Garden, is the leading company in Britain.
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Martin Brown of trade union Equity said all of those balloted had supported the action and predicted that the performance may not go ahead without the chorus.
"The opera world is appalled that this world-class choir is facing such pay cuts," he said. "We have had fantastic support from the arts world and audiences."
The ENO says it is facing a £5 million (6.5 million euro, $7 million) cut to the grant it receives from the government.
It said in a statement that it was "extremely disappointed" there had been a ballot for strike action before "serious negotiations".
"We are saddened that the action that they (Equity) have chosen seems specifically designed to cause the utmost harm to both the company and our audience," it added.
The ENO performs operas in English and, along with the Royal Opera House based in London's Covent Garden, is the leading company in Britain.
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