Mr Somsak said the first political party that sent representatives to sign-up for the election was the New Democrat Party, which arrived the venue around 3am Monday.
The EC had assigned around 40 officials to spend a night at the stadium.
A total of 26 political parties have filed complaints at Din Daeng police station as they could not get into the Thai-Japanese sports stadium in Din Daeng on Monday morning, the first day of registration of party-list candidates for the election.
The commission will later check with police which parties complained they were unable to register to contest the polls.
For those who lodged complaints with police before 8.30am, the EC would consider that they were applying at the same time.
So far, the EC considered that 35 political parties have already signed up. The EC was expected to draw the ballot numbers today but there is the possibility it may be postponed.
The registration of party party-list candidates ends on Friday.
Anti-government protest leader Suthep Thaugsuban on Sunday night urged protesters to block the venue to prevent election candidates from registering.
On Monday morning, groups of protesters blocked five entrances to the stadium, preventing representatives of political parties from entering.
Later, protesters moved to nearby Din Daeng police station where representative of political parties were filing their complaints with the police.
The EC decided to move election sign-up venue to Din Daeng police station.