As many as 600 people are expected to leave the 1,000-strong HQ once the 90-day consul- tation period with unions and staff is complete on February 15. Staff had originally been told to expect the move by 2008.
A Littlewoods Shop Direct spokesman said: 'We have listened to our staff, who have said: 'Does it need to take that long?''
Chairman David Simons said: 'It  is the maximum number of people that could be affected. My guess is that it will be nearer a couple of hundred, rather than 600.'
He said the business was working hard to offer appropriate packages to encourage staff to make the move and it may have to recruit in Liverpool to cover any shortfall.
However, he said the total number of jobs available at Speke would be less than 2,000.
Union bosses fear that the figure of 600, which accounts for more than a quarter of the 2,100 staff across the Liverpool and Manchester offices, could grow.
Usdaw home shopping representative Val Pugh said: 'We are very disappointed. I don't expect to see many staff at Manchester go [to work at Speke]. The journey to Speke will be beyond the majority of people, with the exception of company management.'
Pugh said the number of people that have been made redundant since the Barclay brothers acquired Littlewoods catalogues business in 2002 and the GUS home shopping business in 2003 now runs into 'thousands'.
The agency catalogue market was struggling well before the Barclay Brothers acquired and merged the businesses. However, Pugh said: 'We are waiting for the company to tell us what they are going to do to stop the decline.'
The retailer said its strategy is to move into smaller, better-targeted catalogues and e-commerce sector, away from the declining agency catalogue market.