By Mark Hannaby
BBC Wales political reporter
The language measure would place legal duties on some organisations
A proposed new law on the Welsh language has been published by the assembly government.
The assembly government says it would place duties on some firms to provide Welsh language services.
Firms in areas such as telecoms, gas and electricity would face sanctions, including fines, if they fail to meet language service delivery standards.
It would also establish the post of a language commissioner and would replace the Welsh Language Board.
As well as public sector bodies, the Welsh language measure will bind certain specified organisations in the private sector to provide services in Welsh, including gas, water and electricity suppliers, bus and railway services, sewerage services and telecommunications.
The language commissioner would replace the Welsh Language Board and work to promote and facilitate the use of Welsh and equality between Welsh and English.
The measure, which would also confirm official status for the Welsh language, has been hailed as "an important and historic step" in strengthening Welsh by First Minister Carwyn Jones.
He said: "The proposed measure provides us with some of the tools we need to ensure that the Welsh language can continue to prosper into the 21st Century alongside the English language."
Heritage Minister Alun Ffred Jones said the measure "will answer the call for Welsh speakers to have the right to receive services in Welsh - and will establish a Welsh language commissioner to enforce these rights."
The assembly government said the measure would modernise the framework for the use of the Welsh language in the delivery of public services.
Over time, current Welsh language schemes would be replaced by Welsh language standards.
The assembly government argues that this would reduce the bureaucratic burden on organisations and create greater consistency for the consumer.
The commissioner would have more powerful enforcement powers than have been available to the Welsh Language Board to ensure that Welsh language services are delivered.
He or she would have the power to investigate complaints from Welsh speakers who believe that their freedom to use Welsh with one another has been interfered with.
Plaid Cymru leader Ieuan Wyn Jones said history would show the measure to be a "significant milestone" in the history of the language, making a real difference to those who wish to use the language in their every-day lives and access services through the medium of Welsh.
He said: "Those people will have rights for the first time in our history, and that can only lead to greater equality, and a nation that is ever-more comfortable with its two languages."
Conservative Welsh language spokesman Paul Davies said the measure required "detailed study".
He added: "All the significant developments in the Welsh language have come under Conservative governments, including the Welsh Language Act, the creation of S4C, and the establishment of the Welsh Language Board.
"We are determined to ensure this new legislation does not erect barriers to businesses in Wales which would damage investment and competitiveness. Nor must it discriminate against English speakers."
Liberal Democrat Eleanor Burnham, said she cautiously welcomed the measure, although she called the document "too long, too cumbersome and something of a damp squib".
She said the measure "dwells heavily on responsibilities rather than rights and I would have liked to see the human rights issue more fully addressed", and "the potential loss of the Welsh Language Board is extremely worrying".
Menna Machreth, chair of the Welsh Language Society (Cymdeithas yr Iaith Gymraeg), said the measure was one way to give Welsh an opportunity of equality with English.
But she added: "This measure doesn't affect much of the private sector. The assembly doesn't have the powers for shops to be included in this measure, which we've been calling for because they are a massive part of day to day lives, and if we want to see the Welsh language as a living language around us, I think the Welsh language should be mainstreamed and pulled into the private sector as well.
"But the important thing is that the assembly should keep their promise of delivering rights for people to use and see and hear the Welsh language from day to day.
The assembly government paid tribute to the Welsh Language Board for its work under the 1993 Welsh Language Act.
The heritage minister will next week make a statement to AMs about the rationale behind the proposed legislation and will then take questions from them.
This will be the first of a number of stages of scrutiny that the measure will be subject to by the national assembly.