Insiders tell TVNewser Tucker Carlson's 6pmET show Tucker is getting the axe, but Carlson stays on as a political contributor to all MSNBC shows at least through the 2008 election. The official announcement, expected tomorrow, will include details about who will replace Tucker at 6pmET as well as other political programming additions. Sources say the network is going to beef up its schedule with more NBC News talent.

In recent days, Jossip, as well as other blogs, ratcheted up the talk that Tucker would be replaced "for a new project." In its 33-month run, Carlson's show has had two names, four time slots and multiple formats. At 6pmET, it builds on its Harbdall lead-in on some days, but loses audience on others.

Carlson is expected to host the show through next week, with his new role and title to take effect March 17. We're told he'll also be reporting from the campaign trail.

After the jump, the Tucker Carlson time warp...

Carlson first came to MSNBC in June, 2005 as host of The Situation With Tucker Carlson at 9pmET. That show originated from MSNBC's New Jersey headquarters. In August 2005, the show was moved to 11pmET. In July 2006, the show was renamed "Tucker" and moved to 4pmET (with a repeat airing at 6pmET). In July 2007 the 4pmET hour was scrapped and it aired live at 6pmET only.