MOSCOW (AP) — Russian President Vladimir Putin's spokesman says a mushrooming diplomatic scandal over the poisoning of an ex-spy in Britain won't disrupt Russia's presidential election.

Dmitry Peskov told reporters Thursday the nerve agent attack on Sergei Skripal "doesn't affect" the campaign for Sunday's election, which he called Russia's top priority.

Peskov strongly denied Russian responsibility in the March 4 attack.

The Russian campaign remains lackluster just three days before the vote. Putin is overwhelmingly expected to win another term after 18 years in power, riding in part on his argument that he must stand up to Western aggressors.

Opposition candidate and former TV star Ksenia Sobchak is holding a big rally Thursday, after breaking down in tears at the final televised debate Wednesday night. She was the only candidate to criticize Putin.