The National Party will step up attempts to reduce drug addiction by introducing hardline anti-gang measures and funding more places in rehabilitation centres.

National leader Bill English and police spokeswoman Paula Bennett announced the $82 million package at a drug treatment centre in Te Atatu this morning.

Of that total, half would be spent on creating 1500 additional drug treatment places and funding education and prevention services.

The other half would be invested in a crackdown on gangs and drug dealers.

That includes giving police new powers to search the cars and houses of gang members at any time to check for firearms.

There would also be higher penalties for manufacturing and distributing synthetic cannabis - from two years to eight years. Penalties would not rise for possession.