The Democratic Party will launch its first television ads of the presidential campaign this weekend, spending a hefty $6 million over one week in key states just as candidate John Kerry (search) stops advertising to save money.

The Democratic National Committee's (search) independent expenditure office, which is legally barred from coordinating ads or strategy with Kerry, has bought airtime in more than a dozen states where Kerry has been on the air, said officials familiar with the laws prohibit both candidates from using any of that money after they accept their party's nomination.

That's because they have accepted public financing for the general election, giving them the same amount — $75 million each — to spend from the day they are nominated until the election on Nov. 2.

Kerry, who will accept the Democratic nomination Thursday at the party's convention in Boston, must make his fund stretch five weeks longer than Bush because the Republican convention is five weeks later. Instead of using any of those dollars, Kerry opted to go dark in August to save as much of the fund as possible for later in the campaign. His latest flight of ads ends Thursday.

The DNC, which has $63 million in the bank and is working to raise an additional $100 million, will fill in that void. Liberal interest groups also plan to run ads but probably at lower levels.

After taking a break from the airwaves during the Democratic convention, Bush, too, will go back on the air in August.

His campaign has bought at least $2 million worth of airtime to continue advertising on national cable networks, and aides say he will continue running ads in local media markets in specific states as well.

Bush taped a new batch of commercials in Crawford, Texas, on Wednesday using the president's 1,600-acre ranch as a backdrop, said White House spokesman Trent Duffy. Bush is at the ranch while Democrats hold their nominating convention.