More than 1.6 million registered voters returned their HST referendum ballot packages by the deadline, according to Elections BC.

"To put the HST referendum in perspective as far as the 1.6 million registered voters that returned referendum ballot packages ... we're at 52 per cent," said Elections BC spokesperson Don Main.

"We had 51 per cent of registered voters participate in the 2009 provincial general election so we're up one per cent."

In comparison, only about 790,000 people turned in their packages for the 2002 mail-based Treaty Negotiations Referendum.

According to Elections BC, there are more than 3 million registered voters in the province.

Elections BC also said despite extensions granted due to the disruption in Canada Post mail service, the revised estimate for the overall cost of the referendum dropped to $8.9 million from $12 million.

The results of the HST referendum are expected to be reported on or about Aug. 25.

The HST referendum is binding and will likely have significant political repercussions whatever the results are.

If voters opt to keep the tax, it could be seen as a victory for the ruling B.C. Liberals, despite prompting an 18-month storm of controversy after they announced the 12-per-cent tax in June 2009.

The uproar ultimately led to the resignation of premier Gordon Campbell last November.

If the HST is rejected, the province must revert to the former system in which a seven-per-cent provincial sales tax and the five-per-cent GST are applied to most purchases and services.

There also will be questions about repayment of the $1.6 billion the federal government transferred to B.C. in exchange for introducing the HST.