Election update, 20 April: Scottish Nationalists and manifestos

Today's major political story, judging by the newspapers' front pages, is a rather old one in two senses. First, we've known for some time that, according to the opinion polls, the Scottish Nationalist Party could hold the balance of power after the election on 7 May.

And second, this isn't quite as unprecedented a situation as David Cameron suggested on the Andrew Marr Show yesterday: Irish nationalist MPs propped up Liberal Party governments in 1886, 1892-1895 and 1910-1915.

Those nationalists demanded support for a single issue: Home Rule. Discussion of what the SNP might want in return for its support of a Labour government leads the Times and Telegraph, with another front-page mention in the Guardian.

We've taken a look at what could in happen in the event of a hung Parliament in two recent articles, here and here.

This week we'll be examining the election manifestos of the main parties in a lot more detail as well as continuing to factcheck claims as they come up.