Voters arrive to cast their votes at a polling station, during the Kairana constituency assembly by-election on Monday. Pic/PTI

The high-profile electoral contest for western Uttar Pradesh's Kairana Lok Sabha seat, where the ruling BJP is locked in a straight fight with a joint Opposition candidate, saw over 54 per cent of the constituency's voters casting their mandate amid complaints of malfunctioning of EVM and VVPAT machines.