Labour has promised a decision on measures to control the use of airguns if it is re-elected at Westminster.
Labour pledged a decision on the use of airguns
Home Secretary Charles Clarke said he would announce the outcome of a review by July.
SNP leader Alex Salmond urged voters to "build a better Scotland" and Scottish Lib Dem leader Jim Wallace was touring his party's top five target seats.
Former Conservative Party leader William Hague was on the campaign trail in Forfar and Arbroath.
There have been calls for a ban on airguns since a Glasgow toddler was killed in an incident earlier this year.
The home secretary said he would announce the outcome of a review with Scottish Justice Minister Cathy Jamieson.
Mr Clarke said no option was ruled out - including a complete ban - but it is thought a more likely outcome is a strict licensing system.
He said: "We are looking at licensing and we are looking at an outright ban.
"We have to find something that is practical.
Charles Clarke vowed to find a 'practical' solution
"There are some people who do use airguns in a perfectly legitimate way.
"But what is not acceptable is the kind of abuse which has led to some appalling crimes here in Scotland but also elsewhere. And that is what we are determined to drive out."
Campaigning in Inverness, Mr Salmond said "only the SNP can beat Labour across Scotland in this election and only the SNP can make Scotland matter".
He highlighted the "tartan tests" of fair pensions, more police, saving Scottish regiments, anti-nuclear policy and an oil fund for future generations.
Mr Salmond said the other parties had failed on these key indicators.
The Conservatives and the SNP both oppose the Common Fisheries Policy and merger of Scotland's regiments but, campaigning in Angus, Mr Hague said only a vote for his party would count.
The former Tory leader said a vote for the SNP "lets Labour off the hook".
Mr Hague said: "The only way to change the policy on these issues is to change the government, and it is evident that the SNP cannot form a UK Government."
The Scottish Liberal Democrat leader was travelling from the Highlands to the Borders in a tour of his party's top target seats.
Mr Wallace was campaigning in the Highland seat of Inverness, Nairn, Badenoch and Strathspey.
He said with Labour undermined over the Iraq War, his party would benefit and restore trust.
Jim Wallace was campaigning in Inverness
Mr Wallace said: "The message about 'Can you really trust Tony Blair and the Labour government at Westminster?', is getting through to the electorate.
"The answer is 'no' and Tony Blair will face the judgement of voters on Thursday."
The Scottish Green Party launched proposals to beat poverty.
The party argues that the outdated and complex benefits structure is neither helping those in poverty - children, pensioners, single parent families - nor delivering the best value for public money.
SSP convener Colin Fox was speaking at an election rally in Lochgilphead where he was emphasising the party's rural issues.
He said: "The SSP offers solutions to this rural crisis and our active membership in areas as far apart as the Western Isles and the Borders illustrates the growing influence of socialism in the Scottish countryside."
Half the size
A poll in the Sunday Mail suggested a 7% fall in Scottish Labour support following renewed controversy over the Iraq War.
The Scottish Opinion poll put Labour support at 40%, down seven from prior to the latest row, the SNP on 21% (+1), Lib Dems on 17% (no change), Tories on 12% (+4), and the Scottish Socialists on 3% (+2).
The poll of 524 people was carried out between 26-28 April and was about half the size of the last survey carried out a week before.
A YouGov internet poll for the Daily Telegraph suggested Labour could lose nine seats in Scotland and put the party at 35%, 9% down on the 2001 election.
It put the Lib Dems on 22% (+6), the SNP on 20% (no change) and the Tories on 19% (+3).
YouGov asked 1,019 adults between 26 and 29 of April.