Ukip's "xenophobic" anti-immigrant message could win over the support of disillusioned former BNP voters in next year's elections, Margaret Hodge has warned.
The senior Labour MP told politics.co.uk it is "too early to say" how much of the BNP's vote will become absorbed into Nigel Farage's party.
Hodge was instrumental in humiliating the BNP in 2010, when she decisively saw off a challenge from party leader Nick Griffin in her Barking seat.
She claimed the latest "wave" of pro-fascist support in British political history had dissipated as a result - and suggested the decline of the BNP meant other parties could look to pick up their support as a result.
"When the BNP disappears as an electoral force, people who are still dissatisfied do look to other parties which to put their vote," she said.
"What Ukip does is it's a bit anti-foreigner, it's a bit anti-European, so it becomes another way in which people can express their anger about the changing nature of their community."
Barking had been identified by the BNP as a target seat after the far-right party had won 12 seats on the borough council. It lost all of them in 2010, but Hodge fears 2014 could be a different story.
"In 2010 we were able to merge the M. Hodge brand which I'd been working on for four years with [that of] the council, and that helped," she added.
"In 2014, it's going to be the council on its own. How many will go through to Ukip, which is much more democratic, and how much will go through to the fringe - the BNP and the English Defence League (EDL)? That will be the challenge... I can't take my foot off the accelerator."
Both the BNP and the EDL remain active in Barking and Hodge claims to be working hard to "counter" their continued presence.
Anti-immigrant tensions in the local community could be reflected across the country more broadly when it comes to the 2014 local and European elections, she believes. Ukip's Farage is aiming to win elections to the European parliament outright.
"A lot of the hostility to Europe as I experienced it in Barking and Dagenham comes from a hostility to immigration and the changing nature of their communities," she explained.
"It's difficult to separate the two issues, and one of the challenges if we ever get to having an in-out referendum on Europe will be separating the economic benefits of being members of the EU from arguments around how immigration is changing communities."