The SNP added to the discomfort of the other main parties with further Scottish council by-election victories confirming its political lead north of the border.

The large swings to the party seen at the general election and in other recent local polls were repeated in the latest contests in which the party held two seats at Falkirk and North Lanarkshire councils.

The by-elections were the latest in a series sparked by the resignation of councillors who were elected as SNP MPs at the general election.

At Falkirk, where John McNally had stepped down as councillor in the Denny and Banknock ward after being elected as Falkirk MP, first-preference voting was: SNP 2,576, Lab 549, C 431, Green 170. The swing from Labour to the SNP was 23%.

At North Lanarkshire, first-count voting in the Wishaw ward, formerly represented by new Motherwell & Wishaw MP Marion Fellows, was: SNP 1,915, Lab 1,230, C 385, Soc 117, Ukip 67, LD 37. Swing from Lab to SNP 21%.

The wins come after the SNP last week held three seats and won one from the Greens on Glasgow City Council and held another on South Lanarkshire Council. Swings from Labour to the Scottish Nationalists ranged from 13% to 25%.

The party earlier held seats on Aberdeen City Council with swings of 20% and 23% from Labour to the SNP as well as 25% in a previous North Lanarkshire Council by-election.

Thirteen new SNP MPs so far have resigned as councillors to focus on their Westminster roles, prompting local by-elections.

Forthcoming contests in such circumstances are:

September 10: Edinburgh City - Deidre Brock (Edinburgh North & Leith); and Midlothian - Owen Thompson (Midlothian);

September 17: South Ayrshire - Corri Wilson (Ayr, Carrick & Cumnock);

October 1: East Ayrshire - Alan Brown (Kilmarnock & Loudoun); and Fife - Peter Grant (Glenrothes);

October 8: Highland - Drew Hendry (Inverness, Nairn, Badenoch & Strathspey).

Labour's candidate at Falkirk (Denny and Banknock), Andy Bell, was suspended by the party shortly before the poll in a row over alleged comments made on social media but his name still appeared for Labour on the ballot paper.