The mayors of both cities say that the FA Cup semi-finals should be moved from Wembley.
The game is scheduled for the weekend of 16 and 17 April.
There will be no trains from either city to or from London from 15 to 18 April.
The game needs to be at a more accessible stadium according to the mayor of Greater Manchester.
Without quick, direct trains, many people will be left with no option but to drive, fly, make overly complex rail journeys or book overnight accommodations.
When you factor in the rising costs of fuel, it is clear that supporters of both clubs attending this game will face excessive cost and hassle - and that is before any environmental impact is considered.
Logistical and safety considerations are included. The M6 is likely to be stretched to capacity by Bank Holiday traffic, with thousands of fans making the long journey south.
A single accident could cause the motorway to be brought to a standstill and fans missing the kick-off.
The engineering works have been scheduled since the beginning of the year and the FA was made aware of them last autumn, according to the pair.
Over the last year, we have heard the slogan " football without fans is nothing" many times. Those words will be meaningless to many if this decision is left to stand and people are priced out of the game or unable to attend for other reasons.
We believe the most obvious solution is to move the game to a more accessible stadium and offer to work with you to make that happen.
Prior to the letter, the FA said it was working with Network Rail and National Express to find a solution so that supporters of both teams can travel to and from the fixture with as little disruption as possible.
There is no issue over the venue for the FA Cup semi-finals, which are between London clubs Crystal Palace and Chelsea.