The best-capitalised mining firm in bitcoin has waded into the block size debate – stating it must be resolved by consensus.

BitFury, previously silent on the hot-button issue, said it will join bitcoin's biggest mining pool in backing Jeff Garzik's "market-led" BIP 100 proposal, which lets miners 'vote' on the size of each block.

CEO Valery Vavilov told CoinDesk:

BitFury noted its preference with a public 'tag' on the blockchain yesterday afternoon. BIP 100 now has support from over 35% of the bitcoin hashrate, more than any other proposal.

If bitcoin transactions continue to grow at their current rate, the network will hit a 'capacity cliff' in the coming year. How to resolve this, or whether to take any action at all, has sparked a 'flame war' raging for nearly five months.

Following the release of Bitcoin XT, Gavin Andresen and Mike Hearn's highly controversial fork to 'opt out' of bitcoin's current 1MB block size limit, industry stakeholders are now picking sides.

In a statement on Monday, several of bitcoin's biggest service providers – including wallets Blockchain, Circle and Xapo – put their weight behind BIP 101, the proposal for an 8MB block size limit that increases over time.

"BIP101 and 8MB blocks are already supported by a majority of the miners and we feel it is time for the industry to unite behind this proposal. Our companies will be ready for larger blocks by December and we will run code that supports this," it read.

While over 39% of the network's hashing power is yet to back any scalability proposal, BitFury rival KnCMiner, alongside several China-based mining pools, is also behind an 8MB increase.

Vavilov is against these proposals, he said, because their growth forecasts don't provide enough "predictive power", so the potential cost of mistakes runs extremely high. He added:

Black and white blocks image via Shutterstock