Published: May 26, 2010 8:59 AM EDT

COVINGTON, La. (AP) - BP is giving it another try and the stakes are high. The oil company plans a "top kill" this morning to choke off the gusher of oil at the bottom of the Gulf of Mexico by force-feeding it heavy drilling mud and cement.

The company says the top kill -- like many other methods never tried a mile underwater -- is no sure thing. BP CEO Tony Hayward pegged its chances of success in this case at 60 percent to 70 percent. And the company says those who want can watch the procedure online.

Live video of the leak has been available for the past few days, and BP says that it will continue throughout the procedure. BP's latest move comes as politicians and others are losing patience with the company over several failed attempts to stop the leak that started more than a month ago after an offshore drilling rig exploded.

Some 7 million gallons of crude have spilled into the sea since, fouling Louisiana's marshes and coating birds and other wildlife.