Labour promises one million Welsh speakers by 2050
Labour's assembly election manifesto will commit to ensuring there are a million people speaking Welsh by 2050.
In 2011, there were 562,000 Welsh speakers, according to the census.
Welsh language campaign group Cymdeithas yr Iaith has previously called for measures that would lead to a million Welsh speakers.
Labour said "common sense" and "common cause" were needed to promote the language. Cymdeithas yr Iaith said the party's move was "encouraging".
Labour assembly candidate Sion Jones said: "The idea that Cymdeithas could have influenced our manifesto in the past is probably hard to imagine, that's just not the case now, and there's a genuine change of attitude on all sides.
"To promote the language, we need common sense, common ground and common cause."
Language campaigners say the next Welsh Government needs to honour any commitment it has made.
Cymdeithas yr Iaith Chairman Jamie Bevan said: "The idea of reaching a million Welsh speakers has provoked cross-party support, and most importantly, public support.
"However, it is relatively easy to commit to a single target.
"In the area of language policy, we have seen a number of key targets set over the years, but ultimately get unfulfilled."
The Welsh Conservatives say they want to see an increase in the numbers speaking Welsh outside the classroom and would also develop a network of "Welsh Language Business Champions".
Plaid Cymru's manifesto makes a commitment to a "genuinely bilingual" Wales and a target that 50% of seven-year-olds will be in Welsh medium education by 2030.
The Liberal Democrats say they would target services at young people in their teens who already speak Welsh as a key group for the future of the language.
The Lib Dems would also introduce special provision for pupils to catch up with their peers in learning Welsh.
UKIP say the Welsh language is a source of pride for the nation and the party would protect the language through Welsh medium education.