AGREED plans to give Holyrood new powers over abortion law, lotteries, and health and safety at work were dropped from the Smith Commission at the 11th hour, leaked drafts have revealed.

The documents show that a range of major powers were set to be devolved to Scotland as part of the Unionist "vow" made during the independence referendum, but were axed in the final days of negotiations.

They included full devolution of abortion law and the creation of a separate Scottish Health & Safety Executive. Both were downgraded to the status of "additional issues for consideration", and may or may not be devolved in future.

Plans to give the Scottish Government more control over the treatment of asylum seekers, and a greater say in the governance of the BBC were also removed at the instigation of Unionist parties.

"A lot of stuff got gutted out of the document in the final couple of days," said one participant.

Although Lord Smith's cross-party commission on more powers backed the devolution of income tax bands and rates, a raft of other taxes also remained live options until the final days.

A draft dated November 21 included proposals to devolve income tax personal allowances, employers' National Insurance contributions, inheritance tax, and the power to create new taxes without Treasury approval. However, these were never adopted into an agreed text.

The leaks shine a light on the intense to-ing and fro-ing between the Smith Commission participants, which reported its "Heads of Agreement" on Thursday after nine cross-party meetings in seven weeks. The deal is due to be translated into draft Westminster legislation by January 25 - Burns Night - and formalised into law after May's General Election.

Although its recommendation to give 16 and 17-year-olds the vote should be enacted before the 2016 Holyrood election, most other aspects could take until 2017 or 2018 to come into play.

The Commission's Labour, Liberal Democrat and Conservative members said the 28-page report had delivered the vow's promise of "extensive new powers".

However, the SNP and Greens, while welcoming the new powers up to a point, said the overall package fell short of public expectations, and more powers were needed to tackle austerity and create jobs.

According to sources close to the Commission, its Labour, LibDem and Tory members were frequently on the phone taking instruction from their parties in London, with the LibDems and Tories particularly exercised about welfare proposals and Labour more focused on tax.

The Commission chairman, Lord Smith of Kelvin, also appeared to give extra weight to the views of the three main Westminster parties, a source said. "The position that Lord Smith took was that if the parties who were either in the current UK government or might be in the next refused to budge on something, he went with it. The Unionist votes seemed to count for more."

The BBC revealed on Friday that a draft version from last Tuesday included late proposals to devolve power to vary Universal Credit. A key plank of Coalition welfare reform, but dogged by delays, Universal Credit is supposed to merge Jobseeker's Allowance, Housing Benefit, Income Support, Working Tax Credit, Child Tax Credit, and Employment and Support Allowance.

But LibDem plans to let Holyrood vary its components were dropped after the UK Cabinet was informed, and only a power to vary the housing cost element remained.

Now the Sunday Herald can reveal other powers agreed by the Commission were later cut.

The most controversial concerned abortion. Although health is devolved, Tony Blair specifically blocked the devolution of abortion when he was prime minister in 1998.

A draft version of the report dated 11.15am on November 26 - the final day of negotiations - stated: "Powers over abortion will be devolved to the Scottish Parliament."

The decision to devolve had been agreed on a 4-1 basis, with only Labour opposed to it. But during the final day, Labour kept pushing its opposition in meetings with Lord Smith, who then raised it again with the other parties.

The Conservatives then sided with Labour and the commitment to devolve abortion was removed.

Patrick Harvie, co-convener of the Scottish Greens, who sat on the Commission, said: "The reaction against devolving abortion in the final few days surprised and disappointed me. Concerns that Scotland would do the wrong thing and undermine women's rights are misplaced. The real threat to women's reproductive rights comes from the voice we hear at Westminster."

Another missing power was the creation of a separate Scottish Health & Safety Executive. This had long been supported by Labour and the trade union movement, but was removed at the behest of the UK Government. Unite said a new body could have helped reduce the average 20 workplace deaths a year in Scotland.

A draft dated November 21 stated: "Power to establish a separate Scottish Health & Safety Executive to set enforcement priorities, goals and objectives in Scotland will be devolved to the Scottish Parliament.

"This body would be required to operate within the reserved UK health & safety framework … [but] set and achieve the health and safety objectives of most relevance and importance to Scotland."

This was struck out and relegated to the "additional issues" annex of the final report, which said the Scottish and UK governments should merely "consider" changes.

The November 21 draft also included an agreement that: "The power to permit the creation and regulation of new lotteries in Scotland will be devolved to the Scottish Parliament." But the final report devolved only the power to "prevent the proliferation" of highly addictive gaming machines known as fixed-odds betting terminals.

Also missing after November 21 was a statement that said: "There will be greater Scottish involvement in BBC governance beyond the current right to have one Trust member and the current Audience Council Scotland."

However, the changes were not all one-way. In many cases, the language was beefed-up in the closing stages, and devolved powers strengthened.

Unionist sources also said SNP Finance Secretary John Swinney readily dropped a demand to devolve pensions, and claimed it was because he felt Scotland's ageing population was best served by pensions funded on a UK-wide basis. He also surprised Unionists by accepting Universal Credit should continue being run by Whitehall - all he wanted was the power to tweak it, a source said.

But despite the concessions on pensions and Universal Credit, First Minister Nicola Sturgeon later complained she did not have enough welfare powers.

A Labour spokesman said: "We would never have done anything that meant women's rights across the UK were not uniform. It's for those who argued for the devolution of abortion to say what they would have done with that power."

LibDem leader Willie Rennie said his party had "changed the weather inside the room by advocating a bold change on welfare".