Many of Nicola Sturgeon’s major policies are under threat after deep divisions emerged in the SNP leadership contest, with rivals attacking key pieces of legislation.

In the last 24 hours, Scottish ministers have announced they are postponing a bill setting up a new multibillion pound national care service until after the contest, and controversial plans to impose a 20p deposit on all drinks bottles and cans is likely to be changed after attacks from small producers and shops.

Both policies have been criticised by candidates competing to replace Sturgeon as Scottish National party leader and first minister later this month after she suddenly announced her resignation in February.

Other policies championed by Sturgeon, including the faster closure of North Sea oilfields to protect the climate and using the next UK election as a de facto independence referendum, have come under attack as the three candidates try to appeal to different groups within the party before voting opens on 13 March.

In further evidence of generational shift in the party following Sturgeon’s departure, the widely respected deputy first minister John Swinney announced on Thursday afternoon that he would leave the Scottish government after nearly 16 years and return to the backbenches once a new first minister had been appointed next month.

The divisions dominated first minister’s questions on Thursday. “This contest is an absolute bin fire,” said Douglas Ross, the Scottish Conservative leader. “The SNP is so split and divided that they even wanted to ban the media from hustings.”

Anas Sarwar, the Scottish Labour leader, said all three candidates were “trashing her record”. The SNP, he added, had “turned in on itself [with] all three candidates falling over themselves to distance themselves from the Scottish government’s flawed policies”.

Sturgeon retorted that since both the Tories and Labour had been riven by divisive leadership battles they were in no place to condemn the SNP.

Want to see more SNP fails? – Health Matters